72T36135ML6BBGI [IDT]
FIFO, 512KX36, 3.8ns, Synchronous, CMOS, PBGA240, 19 X 19 MM, 1 MM PITCH, GREEN, PLASTIC, BGA-240;型号: | 72T36135ML6BBGI |
厂家: | INTEGRATED DEVICE TECHNOLOGY |
描述: | FIFO, 512KX36, 3.8ns, Synchronous, CMOS, PBGA240, 19 X 19 MM, 1 MM PITCH, GREEN, PLASTIC, BGA-240 时钟 先进先出芯片 内存集成电路 |
文件: | 总49页 (文件大小:508K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
2.5V 18M-BIT HIGH-SPEED TeraSyncTM
FIFO36-BITCONFIGURATIONS
524,288 x 36
IDT72T36135M
• Separate SCLK input for Serial programming of flag offsets
• Auto power down minimizes standby power consumption
• Master Reset clears entire FIFO
• Partial Reset clears data, but retains programmable settings
• Empty and Full flags signal FIFO status
• Select IDT Standard timing (using EF[1:2] and FF[1:2] flags) or First
Word Fall Through timing (using OR[1:2] and IR[1:2] flags)
• Output enable puts data outputs into high impedance state
• JTAG port, provided for Boundary Scan function
• Available in 240-pin (19mm x 19mm)Plastic Ball Grid Array (PBGA)
50% more space saving than the leading 9M-bit FIFOs
• Independent Read and Write Clocks (permit reading and writing
simultaneously)
FEATURES:
• Industry’s largest FIFO memory organization:
IDT72T36135
• Up to 200 MHz Operation of Clocks
• Functionally and pin compatible to 9Mbit IDT72T36125 TeraSync
devices
⎯
524,288 x 36 - 18M-bits
• User selectable HSTL/LVTTL Input and/or Output
• User selectable Asynchronous read and/or write port timing
• Mark & Retransmit, resets read pointer to user marked position
• Write Chip Select (WCS) input disables Write Port
• Read Chip Select (RCS) synchronous to RCLK
• Programmable Almost-Empty and Almost-Full flags, each flag can
default to one of eight preselected offsets
• Program programmable flags by either serial or parallel means
• Selectable synchronous/asynchronous timing modes for Almost-
Empty and Almost-Full flags
• High-performance submicron CMOS technology
• Industrial temperature range (–40°C to +85°C) is available
• Green parts available, see ordering information
FUNCTIONALBLOCKDIAGRAM
D0 -Dn (x36)
LD SEN
SCLK
WEN
WCLK/WR
WCS
INPUT REGISTER
OFFSET REGISTER
FF/IR[1:2]
PAF[1:2]
EF/OR[1:2]
PAE[1:2]
WRITE CONTROL
LOGIC
ASYW
FLAG
LOGIC
FWFT/SI
PFM
WRITE POINTER
RAM ARRAY
524,288 x 36
FSEL0
FSEL1
MRS
PRS
READ POINTER
RESET
LOGIC
TCK
TRST
TMS
TDO
JTAG CONTROL
(BOUNDARY
SCAN)
RT
MARK
READ
CONTROL
LOGIC
OUTPUT REGISTER
ASYR
TDI
Vref
WHSTL
RHSTL
SHSTL
HSTL I/0
CONTROL
RCLK/RD
REN
RCS
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OE
Q0 -Qn (x36)
IDT and the IDT logo are registered trademarks of Integrated Device Technology, Inc. The TeraSync FIFO is a trademark of Integrated Device Technology, Inc.
FEBRUARY 2009
COMMERCIAL AND INDUSTRIAL TEMPERATURE RANGES
1
©
2009 Integrated Device Technology, Inc. All rights reserved. Product specifications subject to change without notice.
DSC-6723/4
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
PINCONFIGURATION
A1 BALL PAD CORNER
A
B
C
D
E
F
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ VDDQ
VCC
VCC
VCC
VCC
WCLK
WEN
WCS
GND
GND
GND
VDDQ
VDDQ
VDDQ
ASYR
FF1
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
VCC
RCLK
PRS
MRS
LD
FF2
EF1
OE
VCC
VCC
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
VDDQ
PAF1
REN
MARK
EF2
RCS
RT
VCC
PAF2 PAE1
VDDQ
PFM
GND
FSEL0 SHSTL FSEL1 GND
GND
RHSTL
VCC FWFT/SI
PAE2
DNC
VCC
VCC
GND
GND
GND
GND
G
H
J
SCLK
VCC
VCC
VCC
D35
D32
D29
D26
VCC
VCC
VCC
VCC
D33
D30
D27
D24
WHSTL
VDDQ
VDDQ
VDDQ
VDDQ
SEN
VCC
VCC
GND
GND
VDDQ VDDQ
VDDQ VDDQ
ASYW
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
VREF
K
L
GND
GND
GND
GND
GND
VDDQ
VDDQ
Q33
VDDQ
Q35
Q32
Q29
Q26
VCC
D34
D31
D28
D25
DNC
GND
GND
GND
GND
VDDQ
Q34
Q31
Q28
Q25
M
N
P
R
T
Q30
Q27
D21
D19
D18
D22
D20
D17
D23
D13
GND
D10
D11
GND
D5
GND
D4
GND
D1
GND
TMS
GND
TDO
TDI
GND
GND
GND
GND
Q0
GND
Q2
GND
Q3
GND
Q8
GND
Q11
Q12
Q24
Q14
Q15
Q23
Q21
Q18
Q22
Q20
U
V
Q6
Q5
Q9
D14
D7
D8
D2
TRST
Q1
Q19
VCC
D16
D15
Q7
Q10
Q13
Q17
D0
DNC
Q4
VDDQ
D12
D9
D6
D3
Q16
TCK
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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NOTE:
1. DNC - Do Not Connect.
PBGA: 1mm pitch, 19mm x 19mm (BB240-1, order code: BB)
TOP VIEW
FEBRUARY04,2009
2
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
ForapplicationsrequiringmoredatastoragecapacitythanasingleFIFO
canprovide,theFWFTtimingmodepermitsdepthexpansionbychainingFIFOs
inseries(i.e.thedataoutputsofoneFIFOareconnectedtothecorresponding
data inputs of the next). No external logic is required.
DESCRIPTION:
The IDT72T36135M is an exceptionally deep, extrememly high speed,
CMOSFirst-In-First-Out(FIFO)memoriywithclockedreadandwritecontrols
and a wide extended x36 bus to allow ample data flow. These FIFOs offer
severalkeyuserbenefits:
The 18M-bitTeraSyncFIFO has 8flagpins, EF/OR[1:2] (EmptyFlagor
Output Ready), FF/IR[1:2] (Full Flag or Input Ready), PAE[1:2] (Program-
mableAlmost-Emptyflag)andPAF[1:2](ProgrammableAlmost-Fullflag). The
EF[1:2]andFF[1:2]functionsareselectedinIDTStandardmode. TheIR[1:2]
andOR[1:2]functionsareselectedinFWFTmode.PAE[1:2]andPAF[1:2]are
alwaysavailableforuse,irrespectiveoftimingmode. Each flaghasadouble
becausethe18MFIFOwas designedas aMulti-chipModule,soeachsetof
flagssupportsitsrespectiveinternal9MFIFO. Someextraexternalgatinglogic
willhavetobeusedtoaccuratelyreadeachflagoutput. Thiswillbecovered
intheflaggingsectionofthedatasheet.
PAE[1:2]andPAF[1:2]canbeprogrammedindependentlytoswitchatany
pointinmemory. Programmableoffsetsdeterminetheflagswitchingthreshold
andcanbeloadedbytwomethods:parallelorserial. Eightdefaultoffsetsettings
arealsoprovided,sothatPAE[1:2]canbesettoswitchatapredefinednumber
oflocationsfromtheemptyboundaryandthePAF[1:2]thresholdcanalsobe
setatsimilarpredefinedvaluesfromthefullboundary. Thedefaultoffsetvalues
are setduringMasterResetbythe state ofthe FSEL0, FSEL1, andLD pins.
For serial programming, SEN together with LD on each rising edge of
SCLK,areusedtoloadtheoffsetregistersviatheSerialInput(SI). Forparallel
programming,WENtogetherwithLDoneachrisingedgeofWCLK,areused
toloadtheoffsetregistersviaDn. RENtogetherwithLDoneachrisingedge
ofRCLKcanbeusedtoreadtheoffsetsinparallelfromQnregardlessofwhether
serialorparalleloffsetloadinghasbeenselected.
•
•
•
•
•
•
Highdensityofferingof18Mbit
200MHzR/WClockssupporting7.2Gbpsofdatathroughput
UserselectableMARKlocationforretransmit
User selectable I/O structure for HSTL or LVTTL
Asynchronous/Synchronoustranslationonthereadorwriteports
Thefirstworddatalatencyperiod,fromthetimethefirstwordiswritten
to an empty FIFO to the time it can be read, is fixed and short.
TeraSyncFIFOsareparticularlyappropriatefornetwork,video,telecom-
munications,datacommunicationsandotherapplicationsthatneedtobuffer
largeamounts ofdataatveryhighperformance.
Theinput portcanbeselectedaseitheraSynchronous(clocked)interface,
or Asynchronous interface. During Synchronous operation the input port is
controlledbyaWriteClock(WCLK)inputandaWriteEnable(WEN)input. Data
presentontheDndatainputs is writtenintotheFIFOoneveryrisingedgeof
WCLKwhenWENisasserted.DuringAsynchronousoperationonlytheWR
inputisusedtowritedataintotheFIFO.DataiswrittenonarisingedgeofWR,
theWENinputshouldbetiedtoitsactivestate,(LOW).
The inputportcanbe selectedforeither2.5VLVTTLorHSTLoperation,
thisoperationisselectedbythestateoftheWHSTLinputduringamasterreset.
AWrite ChipSelectinput(WCS)is providedforuse whenthe write portis in
bothLVTTLandHSTLmodes.DuringoperationtheWCS inputcanbeused
todisablewriteportinputs (dataonly).
TheoutputportcanbeselectedaseitheraSynchronous(clocked)interface,
orAsynchronousinterface.DuringSynchronousoperationtheoutputportis
controlledbyaReadClock(RCLK)inputandReadEnable(REN)input. Data
is read from the FIFO on every rising edge of RCLK when REN is asserted.
DuringAsynchronousoperationonlytheRDinputisusedtoreaddatafromthe
FIFO.Datais readonarisingedgeofRD,theRENinputshouldbetiedtoits
activestate,LOW.WhenAsynchronousoperationisselectedontheoutputport
theFIFOmustbeconfiguredforStandardIDTmode,alsotheRCSshouldbe
tiedLOWandtheOEinputusedtoprovidethree-statecontroloftheoutputs,Qn.
Theoutputportcanbeselectedforeither2.5VLVTTLorHSTLoperation,
thisoperationisselectedbythestateoftheRHSTLinputduringamasterreset.
AnOutputEnable(OE)inputisprovidedforthree-statecontroloftheoutputs.
AReadChipSelect(RCS)inputisalsoprovided,theRCSinputissynchronized
tothereadclock,andalsoprovidesthree-statecontroloftheQndataoutputs.
When RCS is disabled, the data outputs will be high impedance. During
Asynchronousoperationoftheoutputport,RCSshouldbeenabled,heldLOW.
ThefrequenciesofboththeRCLKandtheWCLKsignalsmayvaryfrom0
tofMAXwithcompleteindependence. Therearenorestrictionsonthefrequency
oftheoneclockinputwithrespecttotheother.
DuringMasterReset(MRS)thefollowingeventsoccur: thereadandwrite
pointers are set to the first location of the FIFO. The FWFT pin selects IDT
Standardmode orFWFTmode.
The Partial Reset (PRS) also sets the read and write pointers to the first
location of the memory. However, the timing mode, programmable flag
programmingmethod,anddefaultorprogrammedoffsetsettingsexistingbefore
PartialResetremainunchanged.Theflagsareupdatedaccordingtothetiming
modeandoffsetsineffect. PRSisusefulforresettingadeviceinmid-operation,
whenreprogrammingprogrammableflagswouldbeundesirable.
Itisalsopossibletoselectthetimingmode of thePAE[1:2](Programmable
Almost-Emptyflag)andPAF[1:2](ProgrammableAlmost-Fullflag)outputs.The
timing modes can be set to be either asynchronous or synchronous for the
PAE[1:2]andPAF[1:2]flags.
IfasynchronousPAE/PAF[1:2]configurationisselected, thePAE[1:2]is
assertedLOWontheLOW-to-HIGHtransitionofRCLK.PAE[1:2]isresetto
HIGH on the LOW-to-HIGH transition of WCLK. Similarly, the PAF[1:2] is
assertedLOWontheLOW-to-HIGHtransitionofWCLKandPAF[1:2]isreset
toHIGHontheLOW-to-HIGHtransitionofRCLK.
If synchronous PAE/PAF[1:2] configuration is selected , the PAE[1:2] is
assertedandupdatedontherisingedgeofRCLKonlyandnotWCLK.Similarly,
PAF[1:2] is asserted and updated on the rising edge of WCLK only and not
RCLK.ThemodedesiredisconfiguredduringMasterResetbythestateofthe
Programmable Flag Mode (PFM) pin.
ThisdeviceincludesaRetransmitfromMarkfeaturethatutilizestwocontrol
inputs,MARKand,RT(Retransmit).IftheMARKinputisenabledwithrespect
totheRCLK,thememorylocationbeingreadatthatpointwillbemarked.Any
subsequentretransmitoperation,RTgoesLOW,willresetthereadpointerto
this‘marked’location.
Therearetwopossibletimingmodesofoperationwiththesedevices:IDT
Standard mode and First Word Fall Through (FWFT) mode.
InIDTStandardmode,thefirstwordwrittentoanemptyFIFOwillnotappear
onthedataoutputlinesunlessaspecificreadoperationisperformed.Aread
operation,whichconsistsofactivatingRENandenablingarisingRCLKedge,
willshiftthewordfrominternalmemorytothedataoutputlines.
InFWFTmode,thefirstwordwrittentoanemptyFIFOisclockeddirectly
tothedataoutputlinesafterthreetransitionsoftheRCLKsignal.ARENdoes
not have to be asserted for accessing the first word. However, subsequent
wordswrittentotheFIFOdorequireaLOWonRENforaccess. Thestateof
theFWFT/SIinputduringMasterResetdeterminesthetimingmodeinuse.
If,atanytime,theFIFOisnotactivelyperforminganoperation,thechipwill
automaticallypowerdown.Onceinthepowerdownstate,thestandbysupply
currentconsumptionisminimized. Initiatinganyoperation(byactivatingcontrol
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
DESCRIPTION (CONTINUED)
accountforJTAGtestingsincethedeviceisaMCM.PleaseseeJTAGsection
forfurtherdetails.
inputs)willimmediatelytakethedeviceoutofthepowerdownstate.
Both an Asynchronous Output Enable pin (OE) and Synchronous Read
ChipSelectpin(RCS)areprovidedontheFIFO.TheSynchronousReadChip
SelectissynchronizedtotheRCLK.Boththeoutputenableandreadchipselect
control the output buffer of the FIFO, causing the buffer to be either HIGH
impedanceorLOWimpedance.
AJTAGtestportisprovided,heretheFIFOhasfullyfunctionalBoundary
Scan feature, compliant with IEEE 1449.1 Standard Test Access Port and
Boundary Scan Architecture. Special consideration should be taken into
TheTeraSyncFIFOhas thecapabilityofoperatingits ports (writeand/or
read)ineitherLVTTLorHSTLmode,eachportsselectionindependentofthe
other.ThewriteportselectionismadeviaWHSTLandthereadportselection
viaRHSTL.AnadditionalinputHSTLisalsoprovided,thisallowstheuserto
selectHSTLoperationforotherpinsonthedevice(notassociatedwiththewrite
or read ports).
TheIDT72T36135MisfabricatedusingIDT’shighspeedsubmicronCMOS
technology.
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
PARTIAL RESET (PRS) MASTER RESET (MRS)
WRITE CLOCK (WCLK/WR)
READ CLOCK (RCLK/RD)
WRITE ENABLE (WEN)
READ ENABLE (REN)
OUTPUT ENABLE (OE)
WRITE CHIP SELECT (WCS)
LOAD (LD)
READ CHIP SELECT (RCS)
(x36) DATA IN (D
0
- D
n)
(x36) DATA OUT (Q0 - Qn)
IDT
72T36135M
RCLK
SERIAL CLOCK (SCLK)
REN
SERIAL ENABLE(SEN)
MARK
FIRST WORD FALL THROUGH/
SERIAL INPUT (FWFT/SI)
RETRANSMIT (RT)
EMPTY FLAG/OUTPUT READY (EF/OR[1:2])
PROGRAMMABLE ALMOST-EMPTY (PAE[1:2])
FULL FLAG/INPUT READY (FF/IR[1:2])
PROGRAMMABLE ALMOST-FULL (PAF[1:2])
6723 drw03
Figure 1. Single Device Configuration Signal Flow Diagram
FEBRUARY04,2009
5
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
PINDESCRIPTION
Symbol
Name
I/OTYPE
Description
(1)
ASYR Asynchronous
LVTTL
INPUT
AHIGHonthisinputduringMasterResetwillselectSynchronousreadoperationfortheoutputport.ALOW
willselectAsynchronousoperation.IfAsynchronousisselectedtheFIFOmustoperateinIDTStandardmode.
ReadPort
(1)
ASYW Asynchronous
LVTTL
INPUT
AHIGHonthisinputduringMasterResetwillselectSynchronouswriteoperationfortheinputport.ALOW
willselectAsynchronousoperation.
WritePort
D0–D35 DataInputs
HSTL-LVTTL Datainputs fora36-bitbus.
INPUT
EF/OR Empty Flag/
HSTL-LVTTL IntheIDTStandardmode,theEF[1:2]functionisselected.EF[1:2]indicateswhetherornottheFIFOmemory
OUTPUT isempty.InFWFTmode,theOR[1:2]functionisselected.OR[1:2]indicateswhetherornotthereisvaliddata
available atthe outputs. Please see Flaggingsectionforexternalgatinginstructions ofthese flags.
[1:2]
OutputReady
FF/IR
[1:2]
Full Flag/
Input Ready
HSTL-LVTTL IntheIDTStandardmode,theFF[1:2]functionisselected.FF[1:2]indicateswhetherornottheFIFOmemory
OUTPUT isfull.IntheFWFTmode,theIR[1:2]functionisselected. IR[1:2]indicateswhetherornotthereisspaceavailable
for writing to the FIFO memory. Please see Flagging section for external gating instructions of
these flags.
FSEL0(1) FlagSelectBit0
FSEL1(1) FlagSelectBit1
FWFT/ FirstWordFall
LVTTL
INPUT
DuringMasterReset,thisinputalongwithFSEL1andtheLDpin,willselectthedefaultoffsetvaluesforthe
programmableflagsPAE[1:2]andPAF[1:2].Thereareuptoeightpossiblesettingsavailable.
LVTTL
INPUT
DuringMasterReset,thisinputalongwithFSEL0andtheLDpinwillselectthedefaultoffsetvaluesforthe
programmableflagsPAE[1:2]andPAF[1:2].Thereareuptoeightpossiblesettingsavailable.
HSTL-LVTTL DuringMasterReset,selects FirstWordFallThroughorIDTStandardmode.AfterMasterReset,this pin
SI
Through/Serial In
INPUT
functionsasaserialinputforloadingoffsetregisters.IfAsynchronousoperationofthereadporthasbeen
selectedthentheFIFOmustbeset-upinIDTStandardmode.
LD
Load
HSTL-LVTTL This is a dual purpose pin. During Master Reset, the state of the LD input along with FSEL0 and FSEL1,
INPUT
determinesoneofeightdefaultoffsetvaluesforthePAE[1:2]andPAF[1:2]flags,alongwiththemethodbywhich
theseoffsetregisterscanbeprogrammed,parallelorserial(seeTable1).AfterMasterReset,thispinenables
writingtoandreadingfromtheoffsetregisters.
MARK MarkforRetransmit HSTL-LVTTL Whenthispinisassertedthecurrentlocationofthereadpointerwillbemarked.AnysubsequentRetransmit
INPUT operationwillresetthereadpointertothisposition.
HSTL-LVTTL MRSinitializes thereadandwritepointers tozeroandsets theoutputregistertoallzeroes.DuringMaster
MRS
MasterReset
INPUT
Reset,theFIFOisconfiguredforeitherFWFTorIDTStandardmode,Synchronous/Asynchronousoperation
ofthereadorwriteport,oneofeightprogrammableflagdefaultsettings,serialorparallelprogrammingof
theoffsetsettings,zerolatencytimingmode,andsynchronousversusasynchronousprogrammableflag
timingmodes.
OE
OutputEnable
HSTL-LVTTL OEprovidesAsynchronousthree-statecontrolofthedataoutputs,Qn.DuringaMasterorPartialResetthe
INPUT OEinputistheonlyinputthatprovideHigh-Impedancecontrolofthedataoutputs.
PAE
[1:2]
Programmable
Almost-EmptyFlag
HSTL-LVTTL PAE[1:2] goes LOWifthenumberofwords intheFIFOmemoryis less thanoffsetn,whichis storedinthe
OUTPUT EmptyOffsetregister. PAE[1:2] goes HIGHifthenumberofwords intheFIFOmemoryis greaterthanor
equal to offset n. Please see Flagging section for external gating instructions of these flags.
PAF
[1:2]
Programmable
Almost-FullFlag
HSTL-LVTTL PAF[1:2]goesHIGHifthenumberoffreelocationsintheFIFOmemoryismorethanoffsetm,whichisstored
OUTPUT intheFullOffsetregister.PAF[1:2]goesLOWifthenumberoffreelocationsintheFIFOmemoryislessthan
or equal to m. Please see Flagging section for external gating instructions of these flags.
(1)
PFM
Programmable
Flag Mode
LVTTL DuringMasterReset,aLOWonPFMwillselectAsynchronousProgrammableflagtimingmode.AHIGHon
INPUT
PFMwillselectSynchronousProgrammableflagtimingmode.
PRS
PartialReset
HSTL-LVTTL PRSinitializesthereadandwritepointerstozeroandsetstheoutputregistertoallzeroes.DuringPartialReset,
INPUT
theexistingmode(IDTorFWFT),programmingmethod(serialorparallel),andprogrammableflagsettings
are allretained.
Q0–Q35 DataOutputs
RCLK/ ReadClock/
HSTL-LVTTL Dataoutputsforan36-bitbus.
OUTPUT
HSTL-LVTTL IfSynchronousoperationofthereadporthasbeenselected,whenenabledbyREN,therisingedgeofRCLK
RD
ReadStobe
INPUT
readsdatafromtheFIFOmemoryandoffsetsfromtheprogrammableregisters.IfLDisLOW,thevalues
loadedintotheoffsetregistersisoutputonarisingedgeofRCLK.IfAsynchronousoperationoftheread
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
PINDESCRIPTION(CONTINUED)
Symbol
Name
I/OTYPE
HSTL-LVTTL port has been selected, a rising edge on RD reads data from the FIFO in an Asynchronous manner.
INPUT RENshouldbetiedLOW.
ReadChipSelect HSTL-LVTTL RCSprovidessynchronouscontrolofthereadportandoutputimpedanceofQn,synchronoustoRCLK.During
Description
RCLK/ ReadClock/
RD
ReadStrobe
RCS
INPUT
aMasterResetorPartialResettheRCSinputis don’tcare,ifOE is LOWthedataoutputs willbe
Low-ImpedanceregardlessofRCS.
REN
ReadEnable
HSTL-LVTTL IfSynchronous operationofthereadporthas beenselected,RENenablesRCLKforreadingdatafromthe
INPUT
FIFOmemoryandoffsetregisters.IfAsynchronousoperationofthereadporthasbeenselected,theREN
inputshouldbetiedLOW.
(1)
RHSTL Read Port HSTL
Select
LVTTL
INPUT
This pin is used to select HSTL or 2.5v LVTTL outputs for the FIFO. If HSTL inputs are required, this input
mustbetiedHIGH.OtherwiseitshouldbetiedLOW.
RT
Retransmit
HSTL-LVTTL RT assertedontherisingedgeofRCLKinitializes theREADpointertozero,sets theEF[1:2]flagtoLOW
INPUT
(OR[1:2]toHIGHinFWFTmode)anddoesn’tdisturbthewritepointer,programmingmethod,existingtiming
modeorprogrammableflagsettings.IfamarkhasbeensetviatheMARKinputpin,thenthereadpointerwill
jumptothe‘mark’location.
SCLK
SerialClock
SerialEnable
HSTL-LVTTL ArisingedgeonSCLKwillclocktheserialdatapresentontheSIinputintotheoffsetregistersprovidingthat
INPUT SEN is enabled.
SEN
HSTL-LVTTL SENenablesserialloadingofprogrammableflagoffsets.
INPUT
SHSTL SystemHSTL
LVTTL
INPUT
AllinputsnotassociatedwiththewriteorreadportcanbeselectedforHSTLoperationviatheSHSTLinput.
Select
(2)
TCK
TRST
TMS
TDI
JTAGClock
JTAGReset
HSTL-LVTTL Clock input for JTAG function. TMS and TDI are sampled on the rising edge of TCK. Data is output on
INPUT TDOonthe fallingedge.
(2)
HSTL-LVTTL TRST is an asynchronous reset pin for the JTAG controller.
INPUT
JTAGMode
Select
HSTL-LVTTL TMS is a serial input pin. Bits are serially loaded on the rising edge of TCK, which selects 1 of 5 modes of
INPUT
HSTL-LVTTL During JTAG boundary scan operation test data is serially loaded via TDI on the rising edge of TCK.
INPUT ThisisalsothedatafortheInstructionRegister,IDRegisterandBypassRegister.
operationforthe JTAGboundaryscan.
TestDataInput
TDO
WEN
TestDataOutput HSTL-LVTTL During JTAG boundary scan operation test data is serially output via TDO on the falling edge of TCK.
OUTPUT This outputis inHigh-Zexceptwhenshifting, while inSHIFT-DRandSHIFT-IRcontrollerstates.
WriteEnable
HSTL-LVTTL WhenSynchronousoperationofthewriteporthasbeenselected,WENenablesWCLKforwritingdatainto
INPUT
theFIFOmemoryandoffsetregisters.IfAsynchronousoperationofthewriteporthasbeenselected,the
WENinputshouldbetiedLOW.
WCS
WriteChipSelect HSTL-LVTTL This pindisables the write portdata inputs whenthe device write portis configuredforHSTLmode. This
INPUT provides added power savings.
WCLK/ WriteClock/
WR WriteStrobe
HSTL-LVTTL If Synchronous operation of the write port has been selected, when enabled by WEN, the rising edge of
INPUT
WCLKwritesdataintotheFIFO.IfAsynchronousoperationofthewriteporthasbeenselected,WRwrites
data into the FIFO on a rising edge in an Asynchronous manner, (WEN shouldbe tiedtoits active state).
(1)
WHSTL WritePortHSTL
Select
LVTTL
INPUT
ThispinisusedtoselectHSTLor2.5VLVTTLinputsfortheFIFO.IfHSTLinputsarerequired,thisinputmust
betiedHIGH.OtherwiseitshouldbetiedLOW.
Vcc
+2.5v Supply
GroundPin
Power
GND
I
These are Vccsupplyinputs andmustbe connectedtothe 2.5Vsupplyrail.
These are Ground pins an dmust be connected to the GND rail.
GND
Vref
Reference
Voltage
ThisisaVoltageReferenceinputandmustbeconnectedtoavoltageleveldeterminedfromthetable,
“RecommendedDCOperatingConditions”.This provides thereferencevoltagewhenusingHSTLclass
inputs.IfHSTLclass inputs arenotbeingused,this pinshouldbetiedLOW.
VDDQ
O/PRailVoltage
I
This pin should be tied to the desired voltage rail for providing power to the output drivers.
NOTES:
1. Inputs should not change state after Master Reset.
2. If the JTAG feature is not being used, TCK and TRST should be tied LOW.
FEBRUARY04,2009
7
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
ABSOLUTEMAXIMUMRATINGS
CAPACITANCE(TA = +25°C, f = 1.0MHz)
Parameter(1)
Conditions
Max.
Unit
Symbol
Rating
Commercial
Unit
Symbol
VTERM
TerminalVoltage
with respect to GND
–0.5to+3.6(2)
V
(2,3)
CIN
Input
Capacitance
VIN = 0V
15(3)
pF
(1,2)
TSTG
IOUT
StorageTemperature
DCOutputCurrent
–55 to +125
–50 to +50
°C
mA
COUT
Output
Capacitance
VOUT = 0V
10.5
pF
NOTES:
NOTES:
1. With output deselected, (OE ≥ VIH).
2. Characterized values, not currently tested.
3. CIN for Vref is 40pF.
1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause
permanent damage to the device. This is a stress rating only and functional operation
of the device at these or any other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect reliability.
2. Compliant with JEDEC JESD8-5. VCC terminal only.
RECOMMENDED DC OPERATING CONDITIONS
Symbol
VCC
Parameter
Min.
2.375
0
Typ.
2.5
0
Max.
2.625
0
Unit
V
SupplyVoltage
SupplyVoltage
GND
V
VIH
InputHighVoltage
⎯ LVTTL
⎯ eHSTL
⎯ HSTL
1.7
VREF+0.2
VREF+0.2
—
—
—
3.45
VDDQ+0.3
VDDQ+0.3
V
V
V
VIL
InputLowVoltage
⎯ LVTTL
⎯ eHSTL
⎯ HSTL
-0.3
-0.3
-0.3
—
—
—
0.7
VREF-0.2
VREF-0.2
V
V
V
VREF(1)
TA
VoltageReferenceInput ⎯ eHSTL
⎯ HSTL
0.8
0.68
0.9
0.75
1.0
0.9
V
V
OperatingTemperatureCommercial
OperatingTemperatureIndustrial
0
—
—
70
85
°C
°C
TA
-40
NOTE:
1. VREF is only required for HSTL or eHSTL inputs. VREF should be tied LOW for LVTTL operation.
2. Outputs are not 3.3V tolerant.
FEBRUARY04,2009
8
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
DCELECTRICALCHARACTERISTICS
(Commercial: VCC = 2.5V ± 0.125V, TA = 0°C to +70°C;Industrial: VCC = 2.5V ± 0.125V, TA = -40°C to +85°C)
Symbol
ILI
Parameter
Min.
–10
Max.
10
Unit
µA
µA
V
V
V
InputLeakageCurrent
ILO
OutputLeakageCurrent
OutputLogic“1”Voltage,
–10
10
(5)
VOH
IOH = –8 mA @VDDQ = 2.5V 0.125V (LVTTL)
IOH = –8 mA @VDDQ = 1.8V 0.1V (eHSTL)
IOH = –8 mA @VDDQ = 1.5V 0.1V (HSTL)
VDDQ-0.4
VDDQ-0.4
VDDQ-0.4
—
—
—
VOL
OutputLogic“0”Voltage,
IOL = 8 mA @VDDQ = 2.5V 0.125V (LVTTL)
IOL = 8 mA @VDDQ = 1.8V 0.1V (eHSTL)
IOL = 8 mA @VDDQ = 1.5V 0.1V (HSTL)
—
—
—
0.4V
0.4V
0.4V
V
V
V
ICC1(1,2)
ICC2(1)
Active VCC Current (VCC = 2.5V)
I/O = LVTTL
I/O = HSTL
I/O = eHSTL
—
—
—
120
180
180
mA
mA
mA
Standby VCC Current (VCC = 2.5V) I/O = LVTTL
—
—
—
40
140
140
mA
mA
mA
I/O = HSTL
I/O = eHSTL
NOTES:
1. Both WCLK and RCLK toggling at 20MHz. Data inputs toggling at 10MHz. WCS = HIGH, REN or RCS = HIGH.
2. For the IDT72T36105/72T36115/72T36135M, typical ICC1 calculation (with data outputs in Low-Impedance):
-3.For all devices, typical IDDQ calculation: with data outputs in High-Impedance: IDDQ (mA) = 0.15 x fs, fs = WCLK = RCLK frequency (in MHz)
with data outputs in Low-Impedance: IDDQ (mA) = (CL x VDDQ x fs x N)/2000
fs = WCLK = RCLK frequency (in MHz), VDDQ = 2.5V for LVTTL; 1.5V for HSTL; 1.8V for eHSTL, CL = capacitive load (pf), tA = 25°C,
N = Number of outputs switching.
4. Total Power consumed: PT = (VCC x ICC) + VDDQ x IDDQ).
5. Outputs are not 3.3V tolerant.
FEBRUARY04,2009
9
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
ACELECTRICALCHARACTERISTICS(1)—SYNCHRONOUSTIMING
(Commercial: VCC = 2.5V 5%, TA = 0°C to +70°C;Industrial: VCC = 2.5V 5%, TA = -40°C to +85°C)
Commercial
Com’l & Ind’l
IDT72T36135ML6
IDT72T36135ML5
Symbol
fC
Parameter
Clock Cycle Frequency (Synchronous)
DataAccessTime
Min.
—
0.6
5
Max.
200
3.6
—
—
—
—
—
—
—
—
—
—
—
10
Min.
—
0.6
6
Max.
166
3.8
—
—
—
—
—
—
—
—
—
—
—
10
Unit
MHz
ns
tA
tCLK
tCLKH
tCLKL
tDS
Clock Cycle Time
ns
Clock High Time
2.5
2.5
1.5
0.5
1.5
0.5
1.5
0.5
1.5
0.5
—
100
45
3.0
3.0
2.0
0.5
2.0
0.5
2.0
0.5
2.0
0.5
—
100
45
ns
Clock Low Time
ns
DataSetupTime
ns
tDH
DataHoldTime
ns
tENS
EnableSetupTime
EnableHoldTime
ns
tENH
tLDS
ns
LoadSetupTime
ns
tLDH
LoadHoldTime
ns
tWCSS
tWCSH
fS
WCSsetuptime
WCSholdtime
Clock Cycle Frequency (SCLK)
Serial Clock Cycle
Serial Clock High
ns
ns
MHz
ns
tSCLK
tSCKH
tSCKL
tSDS
—
—
—
—
—
—
—
—
—
—
—
15
—
—
—
—
—
—
—
—
—
—
—
15
ns
Serial Clock Low
45
45
ns
SerialDataInSetup
Serial Data In Hold
SerialEnableSetup
SerialEnable Hold
15
15
ns
tSDH
tSENS
tSENH
tRS
5
5
ns
5
5
ns
5
5
ns
(3)
ResetPulseWidth
10
10
ns
tRSS
ResetSetupTime
15
15
ns
tHRSS
tRSR
tRSF
tWFF
tREF
tPAFS
tPAES
tRCSLZ
HSTLResetSetupTime
4
4
µs
ns
ResetRecoveryTime
10
10
ResettoFlagandOutputTime
Write Clock to FF[1:2] or IR[1:2]
Read Clock to EF[1:2] or OR[1:2]
Write Clock to Synchronous PAF[1:2]
Read Clock to Synchronous PAE[1:2]
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
ns
3.6
3.6
3.6
3.6
3.6
3.6
4
3.7
3.7
3.7
3.7
3.7
3.7
5
ns
ns
ns
ns
(3)
RCLK to Active from High-Z
ns
(3)
tRCSHZ RCLK to High-Z
ns
tSKEW1 Skew time between RCLK and WCLK for EF[1:2] and FF[1:2]
tSKEW2 Skew time between RCLK and WCLK for PAE[1:2] and PAF[1:2]
ns
5
6
ns
NOTES:
1. All AC timings apply to both Standard IDT mode and First Word Fall Through mode.
2. Pulse widths less than minimum values are not allowed.
3. Values guaranteed by design, not currently tested.
4. Industrial temperature range product for 6ns speed grade is available as a standard device. All other speed grades are available by special order.
FEBRUARY04,2009
10
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
ACELECTRICALCHARACTERISTICS⎯ ASYNCHRONOUSTIMING
(Commercial: VCC = 2.5V 5%, TA = 0°C to +70°C;Industrial: VCC = 2.5V 5%, TA = -40°C to +85°C)
Commercial
Com’l & Ind’l
IDT72T36135ML6
IDT72T36135ML5
Symbol
fA
Parameter
Cycle Frequency (Asynchronous)
DataAccessTime
Min.
—
0.6
12
5
Max.
83
Min.
—
0.6
15
7
Max.
66
Unit
MHz
ns
tAA
10
12
tCYC
Cycle Time
—
—
—
—
10
—
—
—
—
12
ns
tCYH
Cycle HIGH Time
ns
tCYL
Cycle LOW Time
5
7
ns
tRPE
Read Pulse after EF[1:2] HIGH
Clock to Asynchronous FF[1:2]
Clock to Asynchronous EF[1:2]
ClocktoAsynchronousProgrammableAlmost-FullFlag
ClocktoAsynchronousProgrammableAlmost-EmptyFlag
10
—
—
—
—
0
12
—
—
—
—
0
ns
tFFA
tEFA
tPAFA
tPAEA
tOLZ
ns
10
12
ns
10
12
ns
10
12
ns
(3)
OutputEnabletoOutputinLowZ
—
3.6
3.6
10
—
3.8
3.8
12
ns
tOE
OutputEnabletoOutputValid
—
—
—
—
—
—
ns
(3)
tOHZ
tHF
OutputEnabletoOutputinHighZ
ns
Clock to HF
ns
NOTES:
1. All AC timings apply to both Standard IDT mode and First Word Fall Through mode.
2. Industrial temperature range product for 6ns speed grade is available as a standard device. All other speed grades are available by special order.
3. Values guaranteed by design, not currently tested.
FEBRUARY04,2009
11
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
HSTL
AC TEST LOADS
1.5V AC TEST CONDITIONS
VDDQ/2
InputPulseLevels
0.25to1.25V
0.4ns
50Ω
InputRise/FallTimes
InputTimingReferenceLevels
OutputReferenceLevels
0.75
Z0 = 50Ω
I/O
10pF
VDDQ/2
6723 drw04
NOTE:
1. VDDQ = 1.5V±.
Figure 2a. AC Test Load
EXTENDEDHSTL
1.8V AC TEST CONDITIONS
6
5
4
3
2
1
InputPulseLevels
0.4 to 1.4V
0.4ns
InputRise/FallTimes
InputTimingReferenceLevels
OutputReferenceLevels
0.9
VDDQ/2
NOTE:
1. VDDQ = 1.8V±.
20 30 50 80 100
Capacitance (pF)
200
6723 drw04a
Figure 2b. Lumped Capacitive Load, Typical Derating
2.5VLVTTL
2.5V AC TEST CONDITIONS
InputPulseLevels
GND to 2.5V
1ns
InputRise/FallTimes
InputTimingReferenceLevels
OutputReferenceLevels
VCC/2
VDDQ/2
NOTE:
1. For LVTTL VCC = VDDQ.
FEBRUARY04,2009
12
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
OUTPUT ENABLE & DISABLE TIMING
Output
Enable
Output
Disable
VIH
OE
VIL
tOE &
tOLZ
tOHZ
V
2
CC
Output
Normally
LOW
V
2
CC
100mV
100mV
100mV
V
OL
V
OH
Output
Normally
HIGH
VCC
100mV
VCC
2
2
6723 drw05
NOTES:
1. REN is HIGH.
2. RCS is LOW.
READ CHIP SELECT ENABLE & DISABLE TIMING
VIH
tENH
RCS
VIL
tENS
RCLK
tRCSHZ
tRCSLZ
Output
Normally
LOW
VCC
2
V
2
CC
100mV
100mV
100mV
VOL
VOH
Output
Normally
HIGH
VCC
100mV
VCC
2
2
6723 drw06
NOTES:
1. REN is HIGH.
2. OE is LOW.
FEBRUARY04,2009
13
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
WhentheFIFOisfull,theFullFlag(FF[1:2])willgoLOW,inhibitingfurther
writeoperations.Ifnoreadsareperformedafterareset,FF[1:2]willgoLOW
afterDwrites tothe FIFO.
FUNCTIONALDESCRIPTION
TIMING MODES: IDT STANDARD vs FIRST WORD FALL THROUGH
(FWFT) MODE
TheIDT72T36135Msupporttwodifferenttimingmodesofoperation:IDT
Standardmode orFirstWordFallThrough(FWFT)mode. The selectionof
whichmodewilloperateisdeterminedduringMasterReset,bythestateofthe
FWFT/SIinput.
If,atthetimeofMasterReset,FWFT/SIisLOW,thenIDTStandardmode
willbeselected.ThismodeusestheEmptyFlag(EF[1:2])toindicatewhether
ornotthereareanywordspresentintheFIFO.ItalsousestheFullFlagfunction
(FF[1:2])toindicatewhetherornottheFIFOhasanyfreespaceforwriting.In
IDTStandardmode,everywordreadfromtheFIFO,includingthefirst,must
be requested using the Read Enable (REN) and RCLK.
If the FIFO is full, the first read operation will cause FF[1:2] to go HIGH.
SubsequentreadoperationswillcausePAF[1:2]togoHIGHattheconditions
describedinTable2.Iffurtherreadoperationsoccur,withoutwriteoperations,
PAE[1:2]willgoLOWwhentherearenwordsintheFIFO,wherenistheempty
offsetvalue.ContinuingreadoperationswillcausetheFIFOtobecomeempty.
When the last word has been read from the FIFO, the EF[1:2] will go LOW
inhibitingfurtherreadoperations. REN is ignoredwhenthe FIFOis empty.
WhenconfiguredinIDTStandardmode,theEF[1:2]andFF[1:2]outputs
aredoubleregister-bufferedoutputs.
Relevanttimingdiagrams forIDTStandardmodecanbefoundinFigure
10, 11, 12 and 17.
If,atthetimeofMasterReset,FWFT/SIisHIGH,thenFWFTmodewillbe
selected.ThismodeusesOutputReady(OR[1:2])toindicatewhetherornot
there is validdata atthe data outputs (Qn). Italsouses InputReady(IR[1:2])
toindicatewhetherornottheFIFOhasanyfreespaceforwriting.IntheFWFT
mode,thefirstwordwrittentoanemptyFIFOgoesdirectlytoQnafterthreeRCLK
rising edges, REN = LOW is not necessary. Subsequent words must be
accessed using the Read Enable (REN) and RCLK.
FIRST WORD FALL THROUGH MODE (FWFT)
In this mode, the status flags, IR[1:2], PAF[1:2], PAE[1:2], and OR[1:2]
operateinthemanneroutlinedinTable3.TowritedataintototheFIFO,WEN
mustbeLOW.DatapresentedtotheDATAINlineswillbeclockedintotheFIFO
onsubsequenttransitionsofWCLK.Afterthefirstwriteisperformed,theOutput
Ready(OR[1:2])flagwillgoLOW.Subsequentwriteswillcontinuetofillupthe
FIFO.PAE[1:2]willgoHIGHaftern + 2wordshavebeenloadedintotheFIFO,
wherenistheemptyoffsetvalue.Thedefaultsettingforthesevaluesarestated
inthefootnoteofTable1.Thisparameterisalsouserprogrammable.Seesection
onProgrammableFlagOffsetLoading.
WhentheFIFOisfull,theInputReady(IR[1:2])flagwillgoHIGH,inhibiting
furtherwriteoperations.Ifnoreadsareperformedafterareset,IR[1:2]willgo
HIGHafterDwritestotheFIFO.NotethattheadditionalwordinFWFTmode
isduetothecapacityofthememoryplusoutputregister.
IftheFIFOisfull,thefirstreadoperationwillcausetheIR[1:2]flagtogoLOW.
SubsequentreadoperationswillcausethePAF[1:2]togoHIGHattheconditions
describedinTable3.Iffurtherreadoperationsoccur,withoutwriteoperations,
the PAE[1:2] willgoLOWwhenthere are n+1words inthe FIFO, where nis
the empty offset value. Continuing read operations will cause the FIFO to
becomeempty.WhenthelastwordhasbeenreadfromtheFIFO,OR[1:2]will
goHIGHinhibitingfurtherreadoperations.RENisignoredwhentheFIFOis
empty.
WhenconfiguredinFWFTmode,theOR[1:2]flagoutputistripleregister-
buffered,andtheIR[1:2]flagoutputisdoubleregister-buffered.
Relevanttimingdiagrams forFWFTmodecanbefoundinFigure13,14,
15 and 18.
Varioussignals,bothinputandoutputsignalsoperatedifferentlydepending
onwhichtimingmodeisineffect.
IDT STANDARD MODE
In this mode, the status flags, FF[1:2], PAF[1:2], PAE[1:2], and EF[1:2]
operateinthemanneroutlinedinTable2.TowritedataintototheFIFO,Write
Enable(WEN)mustbeLOW.DatapresentedtotheDATAINlineswillbeclocked
intotheFIFOonsubsequenttransitionsoftheWriteClock(WCLK).Afterthefirst
writeisperformed,theEmptyFlag(EF[1:2])willgoHIGH.Subsequentwrites
willcontinuetofilluptheFIFO.TheProgrammableAlmost-Emptyflag(PAE[1:2])
willgoHIGHaftern + 1wordshavebeenloadedintotheFIFO,wherenisthe
emptyoffsetvalue.Thedefaultsettingforthesevaluesarestatedinthefootnote
of Table 1. This parameter is also user programmable. See section on
ProgrammableFlagOffsetLoading.
ContinuingtowritedataintotheFIFOwillcausetheProgrammableAlmost-
Fullflag(PAF[1:2])togoLOW.Again,ifnoreadsareperformed,thePAF[1:2]
willgoLOW.Theoffset“m”isthefulloffsetvalue.Thedefaultsettingforthese
values are stated in the footnote of Table 1. This parameter is also user
programmable.SeesectiononProgrammableFlagOffsetLoading.
FEBRUARY04,2009
14
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
PROGRAMMING FLAG OFFSETS
SYNCHRONOUS vs ASYNCHRONOUS PROGRAMMABLE FLAG
TIMING SELECTION
TheIDT72T36135McanbeconfiguredduringtheMasterResetcyclewith
eithersynchronousorasynchronoustimingforPAF[1:2]andPAE[1:2]flagsby
use of the PFM pin.
IfsynchronousPAF/PAE[1:2]configurationisselected(PFM,HIGHduring
MRS),thePAFisassertedandupdatedontherisingedgeofWCLKonlyand
notRCLK. Similarly, PAE[1:2] is assertedandupdatedonthe risingedge of
RCLK only and not WCLK. For detail timing diagrams, see Figure 22 for
synchronousPAF[1:2]timingandFigure23forsynchronousPAE[1:2]timing.
IfasynchronousPAF/PAE[1:2]configurationisselected(PFM,LOWduring
MRS),thePAFisassertedLOWontheLOW-to-HIGHtransitionofWCLKand
PAF[1:2]isresettoHIGHontheLOW-to-HIGHtransitionofRCLK. Similarly,
PAE[1:2]isassertedLOWontheLOW-to-HIGHtransitionofRCLK.PAE[1:2]
is reset to HIGH on the LOW-to-HIGH transition of WCLK. For detail timing
diagrams,seeFigure24forasynchronousPAF[1:2]timingandFigure25for
asynchronousPAE[1:2]timing.
Full and Empty Flag offset values are user programmable. The
IDT72T36135Mhaveinternalregistersfortheseoffsets.Thereareeightdefault
offsetvaluesselectableduringMasterReset.Theseoffsetvaluesareshown
inTable1.OffsetvaluescanalsobeprogrammedintotheFIFOinoneoftwo
ways;serialorparallelloadingmethod.Theselectionoftheloadingmethodis
doneusingtheLD (Load)pin.DuringMasterReset,thestateoftheLD input
determineswhetherserialorparallelflagoffsetprogrammingisenabled.AHIGH
onLDduringMasterResetselectsserialloadingofoffsetvalues.ALOWonLD
duringMasterResetselectsparallelloadingofoffsetvalues.
InadditiontoloadingoffsetvaluesintotheFIFO,itisalsopossibletoread
thecurrentoffsetvalues.Offsetvaluescanbereadviatheparalleloutputport
Q0-Qn,regardlessoftheprogrammingmodeselected(serialorparallel).Itis
notpossibletoreadtheoffsetvaluesinserialfashion.
Figure3,ProgrammableFlagOffsetProgrammingSequence,summaries
thecontrolpinsandsequenceforbothserialandparallelprogrammingmodes.
Foramoredetaileddescription,seediscussionthatfollows.
Theoffsetregistersmaybeprogrammed(andreprogrammed)anytimeafter
MasterReset,regardlessofwhetherserialorparallelprogramminghasbeen
selected.Validprogrammingranges arefrom0toD-1.
TABLE 1 — DEFAULT PROGRAMMABLE TABLE 2 — STATUS FLAGS FOR IDT
FLAG OFFSETS STANDARD MODE
IDT72T36135M
IDT72T36135M
FF PAF PAE EF
0
H
H
H
H
H
H
L
L
H
L
*LD
H
L
L
L
FSEL1
FSEL0
Offsets n,m
Number of
Words in
FIFO
1 to n (1)
H
H
L
H
L
L
L
H
L
H
L
H
H
1,023
511
255
127
63
31
15
7
n + 1 to (524,288-(m+1))
H
L
L
L
H
H
H
H
(524,288-m) to 524,287
524,288
L
NOTE:
L
H
H
L
1. See Table 1 for values for n, m.
H
H
H
H
TABLE 3 — STATUS FLAGS FOR FWFT
MODE
*LD
H
L
FSEL1
FSEL0
Program Mode
(3)
IDT72T36135M
IR
PAF PAE OR
X
X
X
X
Serial
Parallel
(4)
0
L
L
L
H
H
H
L
L
H
H
L
L
Number of
Words in
FIFO
1 to n+1
*THIS PIN MUST BE HIGH AFTER MASTER RESET TO WRITE
OR READ DATATO/FROM THE FIFO MEMORY.
n + 1 to (524,289-(m+1))
L
L
L
H
H
L
(524,289-m) to 524,288
524,289
H
L
NOTES:
6723 drw07
NOTE:
1. n = empty offset for PAE[1:2].
2. m = full offset for PAF[1:2].
1. See Table 1 for values for n, m.
3. As well as selecting serial programming mode, one of the default values will also
be loaded depending on the state of FSEL0 & FSEL1.
4. As well as selecting parallel programming mode, one of the default values will
also be loaded depending on the state of FSEL0 & FSEL1.
FEBRUARY04,2009
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IDT72T36135M
WCLK RCLK
X
SCLK
LD
WEN
REN
SEN
Parallel write to registers:
Empty Offset (LSB)
Empty Offset (MSB)
Full Offset (LSB)
X
0
0
1
1
Full Offset (MSB)
Parallel read from registers:
Empty Offset (LSB)
Empty Offset (MSB)
Full Offset (LSB)
X
X
0
1
0
1
X
Full Offset (MSB)
Serial shift into registers:
0
1
1
1
1
0
1
X
38 bits for the IDT72T36135M
1 bit for each rising SCLK edge
Starting with Empty Offset (LSB)
Ending with Full Offset (MSB)
X
X
X
X
X
No Operation
Write Memory
X
1
1
1
0
X
1
X
0
1
X
X
X
X
X
X
X
Read Memory
X
No Operation
6723 drw08
NOTES:
1. The programming method can only be selected at Master Reset.
2. Parallel reading of the offset registers is always permitted regardless of which programming method has been selected.
3. The programming sequence applies to both IDT Standard and FWFT modes.
1st Parallel Offset Write/Read Cycle
D/Q17
Data Inputs/Outputs
D/Q16
D/Q0
1
EMPTY OFFSET (LSB) REGISTER
16 15 14 13 12 11 10
9 8 7 6 5 4 3 2
# of Bits Used
2nd Parallel Offset Write/Read Cycle
D/Q17
Data Inputs/Outputs
D/Q0
D/Q16
EMPTY OFFSET (MSB) REGISTER
19 18 17
3rd Parallel Offset Write/Read Cycle
D/Q17
D/Q16
Data Inputs/Outputs
FULL OFFSET (LSB) REGISTER
D/Q
0
16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
4th Parallel Offset Write/Read Cycle
D/Q17
Data Inputs/Outputs
D/Q
0
D/Q16
FULL OFFSET (MSB) REGISTER
19 18 17
6723 drw09
NOTE:
1. Consecutive reads of the offset registers is not permitted. The read operation must be disabled for a minimum of
one RCLK cycle in between offset register accesses. (Please refer to Figure 21, Parallel Read of Programmable
Flag Registers (IDT Standard and FWFT Modes) for more details).
Figure 3. Programmable Flag Offset Programming Sequence
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SERIAL PROGRAMMING MODE
writingthepreviousmarklocation.RetransmitoperationisavailableinbothIDT
IfSerialProgrammingmodehasbeenselected,asdescribedabove,then standardandFWFTmodes.
programming of PAE[1:2] and PAF[1:2] values can be achieved by using a
DuringIDTstandardmodetheFIFOisputintoretransmitmodebyaLow-
combinationoftheLD,SEN,SCLKandSIinputpins.ProgrammingPAE[1:2] to-HightransitiononRCLKwhenthe‘MARK’inputisHIGHandEF[1:2]isHIGH.
andPAF[1:2] proceeds as follows:whenLD and SEN are setLOW, data on TherisingRCLKedge‘marks’thedatapresentintheFIFOoutputregisteras
theSIinputarewritten,onebitforeachSCLKrisingedge,startingwiththeEmpty thefirstretransmitdata.TheFIFOremainsinretransmitmodeuntilarisingedge
OffsetLSBandendingwiththeFullOffsetMSB.38bitstotalrequired.SeeFigure on RCLK occurs while MARK is LOW.
19,SerialLoadingofProgrammableFlagRegisters,forthetimingdiagramfor
thismode.
Oncea‘marked’locationhasbeenset(andthedeviceisstillinretransmit
mode,MARKisHIGH),aretransmitcanbeinitiatedbyarisingedgeonRCLK
Using the serial method, individual registers cannot be programmed whiletheretransmitinput(RT)isLOW.RENmustbeHIGH(readsdisabled)
selectively. PAE[1:2] and PAF[1:2] can show a valid status only after the beforebringingRTLOW.Thedeviceindicatesthestartofretransmitsetupby
completesetofbits(foralloffsetregisters)hasbeenentered.Theregisterscan setting EF[1:2] LOW, also preventing reads. When EF[1:2] goes HIGH,
bereprogrammedaslongasthecompletesetofnewoffsetbitsisentered.When retransmitsetupiscompleteandreadoperationsmaybeginstartingwiththefirst
LD is LOW and SEN is HIGH, no serial write to the registers can occur.
dataattheMARKlocation.SinceIDTstandardmodeisselected,everyword
Write operations to the FIFO are allowed before and during the serial readincludingthefirst‘marked’wordfollowingaretransmitsetuprequiresaLOW
programmingsequence. Inthiscase,theprogrammingofalloffsetbitsdoesnot on REN (read enabled).
havetooccuratonce. AselectnumberofbitscanbewrittentotheSIinputand
Note, write operations may continue as normal during all retransmit
then,bybringingLDandSENHIGH,datacanbewrittentoFIFOmemoryvia functions,howeverwriteoperationstothe‘marked’locationwillbeprevented.
DnbytogglingWEN. WhenWENisbroughtHIGHwithLDandSENrestored See Figure 17, Retransmit from Mark (IDT standard mode), for the relevant
toaLOW,thenextoffsetbitinsequenceiswrittentotheregistersviaSI. Ifan timingdiagram.
interruptionofserialprogrammingisdesired,itissufficienteithertosetLDLOW
anddeactivateSENortosetSENLOWanddeactivateLD. OnceLDandSEN edge whenthe ‘MARK’inputis HIGHandOR[1:2] is LOW. The risingRCLK
arebothrestoredtoaLOWlevel,serialoffsetprogrammingcontinues. edge‘marks’thedatapresentintheFIFOoutputregisterasthefirstretransmit
DuringFWFTmodetheFIFOisputintoretransmitmodebyarisingRCLK
Fromthetimeserialprogramminghasbegun,neitherprogrammableflag data. The FIFOremains inretransmitmode untila risingRCLKedge occurs
willbevaliduntilthefullsetofbitsrequiredtofillalltheoffsetregistershasbeen whileMARKisLOW.
written. MeasuringfromtherisingSCLKedgethatachievestheabovecriteria;
PAF[1:2]willbevalidafterthreemorerisingWCLKedgesplustPAF,PAE[1:2] mode,MARKisHIGH),aretransmitcanbeinitiatedbyarisingRCLKedgewhile
will be valid after the next three rising RCLK edges plus tPAE. theretransmitinput(RT)isLOW.RENmustbeHIGH(readsdisabled)before
Onceamarkedlocationhasbeenset(andthedeviceisstillinretransmit
ItisonlypossibletoreadtheflagoffsetvaluesviatheparalleloutputportQn. bringingRTLOW.Thedeviceindicatesthestartofretransmitsetupbysetting
OR[1:2] HIGH.
PARALLELMODE
WhenOR[1:2]goesLOW,retransmitsetupiscompleteandonthenextrising
IfParallelProgrammingmodehasbeenselected,asdescribedabove,then RCLKedgeafterretransmitsetupiscomplete,(RTgoesHIGH),thecontents
programming of PAE[1:2] and PAF[1:2] values can be achieved by using a ofthefirstretransmitlocationareloadedontotheoutputregister.SinceFWFT
combinationoftheLD, WCLK,WENandDninputpins. ProgrammingPAE[1:2] modeisselected,thefirstwordappearsontheoutputsregardlessofREN,a
and PAF[1:2] proceeds as follows: LD and WEN must be set LOW. When LOWonRENisnotrequiredforthefirstword.Readingallsubsequentwords
programming the Offset Registers of the TeraSync FIFO’s the number of requires a LOW on REN to enable the rising RCLK edge. See Figure 18,
programmingcycleswillbebasedonthebuswidth,thefollowingrulesapply: RetransmitfromMarktiming(FWFTmode),fortherelevanttimingdiagram.
4enabledwritecyclesarerequiredtoprogramtheoffsetregisters,(2per
Note,theremustbeaminimumof128wordsofdatabetweenthewritepointer
offset).DataontheinputsDnarewrittenintotheEmptyOffsetRegisteronthe andreadpointerwhentheMARKisasserted.Also,oncetheMARKisset,the
firsttwoLOW-to-HIGHtransitionofWCLK.UponthethirdandfourthLOW-to- write pointer will not increment past the “marked” location until the MARK is
HIGHtransitionofWCLK,dataarewrittenintotheFullOffsetRegister.SeeFigure deasserted.Thisprevents“overwriting”ofretransmitdata.
3, Programmable Flag Offset Programming Sequence for more details.
HSTL/LVTTL I/O
RETRANSMITFROMMARKOPERATION
Both the write port and read port are user selectable between HSTL or
TheRetransmitfromMarkfeatureallowsFIFOdatatobereadrepeatedly LVTTL I/O, via two select pins, WHSTL and RHSTL respectively. All other
startingatauser-selectedposition.TheFIFOisfirstputintoretransmitmodethat controlpins are selectable via SHSTL, see Table 4fordetails ofgroupings.
will‘mark’abeginningwordandalsosetapointerthatwillpreventongoingFIFO
writeoperationsfromover-writingretransmitdata.Theretransmitdatacanbe thepowerconsumption(instand-bymodebyutilizingtheWCSinput).
readrepeatedlyanynumberoftimesfromthe‘marked’position.TheFIFOcan All“StaticPins”mustbe tiedtoVCC orGND. These pins are LVTTLonly,
Note,thatwhenthewriteportisselectedforHSTLmode,theusercanreduce
betakenoutofretransmitmodeatanytimetoallownormaldeviceoperation. andare purelydevice configurationpins.
The‘mark’positioncanbeselectedanynumberoftimes,eachselectionover-
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TABLE 4 — I/O CONFIGURATION
WHSTL SELECT
RHSTL SELECT
SHSTL SELECT
STATIC PINS
WHSTL: HIGH = HSTL
LOW = LVTTL
RHSTL: HIGH = HSTL
LOW = LVTTL
SHSTL: HIGH = HSTL
LOW = LVTTL
LVTTL ONLY
Dn (I/P)
RCLK/RD (I/P)
RCS (I/P)
MARK (I/P)
REN (I/P)
OE (I/P)
EF/OR[1:2] (O/P)
SCLK (I/P)
LD (I/P)
MRS (I/P)
TCK (I/P)
TMS (I/P)
SEN (I/P)
FWFT/SI (I/P)
PRS (I/P)
ASYR (I/P)
FSEL1 (I/P)
SHSTL (I/P)
RHSTL (I/P)
ASYW (I/P)
FSEL0 (I/P)
PFM (I/P)
WCLK/WR (I/P)
WEN (I/P)
WCS (I/P)
PAF[1:2] (O/P)
PAE[1:2] (O/P)
FF/IR[1:2] (O/P)
TDO (O/P)
TRST (I/P)
TDI (I/P)
WHSTL (I/P)
RT (I/P)
Qn (O/P)
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ASYNCHRONOUS READ (ASYR)
SIGNALDESCRIPTION
INPUTS:
ThereadportcanbeconfiguredforeitherSynchronousorAsynchronous
mode of operation. If during a Master Reset the ASYR input is LOW, then
Asynchronous operationofthereadportwillbeselected.DuringAsynchro-
nousoperationofthereadporttheRCLKinputbecomesRDinput,thisisthe
Asynchronousreadstrobeinput.ArisingedgeonRDwillreaddatafromthe
FIFO via the output register and Qn port. (REN must be tied LOW during
Asynchronous operationofthe readport).
DATA IN (D0 - Dn)
Data inputs for 36-bit wide data (D0 - D35).
CONTROLS:
The OE input provides three-state control of the Qn output bus, in an
asynchronousmanner.(RCS,providesthree-statecontrolofthereadportin
Synchronousmode).
WhenthereadportisconfiguredforAsynchronousoperationthedevice
mustbeoperatingonIDTstandardmode,FWFTmodeisnotpermissibleifthe
read port is Asynchronous. The Empty Flag (EF[1:2]) operates in an
Asynchronousmanner,thatis,theemptyflagwillbeupdatedbasedonboth
areadoperationandawriteoperation.Refertofigures 32,33,34and35for
relevanttimingandoperationalwaveforms.
MASTER RESET ( MRS )
AMasterResetisaccomplishedwhenevertheMRSinputistakentoaLOW
state.Thisoperationsetstheinternalreadandwritepointerstothefirstlocation
of the RAM array. PAE[1:2] will go LOW, PAF[1:2] will go HIGH.
If FWFT/SI is LOW during Master Reset then the IDT Standard mode,
alongwithEF[1:2]andFF[1:2]areselected.EF[1:2]willgoLOWandFF[1:2]
will go HIGH. If FWFT/SI is HIGH, then the First Word Fall Through mode
(FWFT),alongwithIR[1:2]andOR[1:2],areselected. OR[1:2]willgoHIGH
and IR[1:2] will go LOW.
AllcontrolsettingssuchasRMandPFMaredefinedduringtheMasterReset
cycle.
DuringaMasterReset,theoutputregisterisinitializedtoallzeroes.AMaster
Resetisrequiredafterpowerup,beforeawriteoperationcantakeplace.MRS
isasynchronous.
RETRANSMIT (RT)
The Retransmit (RT) input is used in conjunction with the MARK input,
togethertheyprovideameansbywhichdatapreviouslyreadoutoftheFIFO
canberereadanynumberoftimes.Ifretransmitoperationhasbeenselected
(i.e.theMARKinputisHIGH),arisingedgeonRCLKwhileRTisLOWwillreset
thereadpointerbacktothememorylocationsetbytheuserviatheMARKinput.
IfIDTstandardmodehasbeenselectedtheEF[1:2]flagwillgoLOWand
remain LOW for the time that RT is held LOW. RT can be held LOW for any
numberofRCLKcycles,thereadpointerbeingresettothemarkedlocation.
ThenextrisingedgeofRCLKafterRThasreturnedHIGH,willcauseEF[1:2]
togoHIGH,allowingreadoperationstobeperformedontheFIFO.Thenext
readoperationwillaccessdatafromthe‘marked’memorylocation.
Subsequentretransmitoperationsmaybeperformed,eachtimetheread
pointerreturningtothe‘marked’location.SeeFigure17,RetransmitfromMark
(IDTStandardmode)forthe relevanttimingdiagram.
IfFWFTmodehasbeenselectedtheOR[1:2]flagwillgoHIGHandremain
HIGHforthetimethatRTis heldLOW.RTcanbeheldLOWforanynumber
ofRCLK cycles,thereadpointerbeingresettothe‘marked’location.Thenext
RCLKrisingedgeafterRThasreturnedHIGH,willcauseOR[1:2]togoLOW
andduetoFWFToperation,thecontentsofthemarkedmemorylocationwill
be loaded onto the output register, a read operation being required for all
subsequentdatareads.
See Figure 8, Master Reset Timing, forthe relevanttimingdiagram.
PARTIAL RESET (PRS)
APartialResetisaccomplishedwheneverthePRS inputistakentoaLOW
state.AsinthecaseoftheMasterReset,theinternalreadandwritepointers
are settothe firstlocationofthe RAMarray,PAE[1:2] goes LOW, PAF[1:2]
goes HIGH.
WhichevermodeisactiveatthetimeofPartialReset,IDTStandardmode
orFirstWordFallThrough,thatmodewillremainselected. IftheIDTStandard
modeisactive,thenFF[1:2]willgoHIGHandEF[1:2]willgoLOW. IftheFirst
WordFallThroughmodeisactive,thenOR[1:2]willgoHIGH,andIR[1:2]will
goLOW.
Following Partial Reset, all values held in the offset registers remain
unchanged. Theprogrammingmethod(parallelorserial)currentlyactiveat
thetimeofPartialResetisalsoretained. Theoutputregisterisinitializedtoall
zeroes. PRS is asynchronous.
A Partial Reset is useful for resetting the device during the course of
operation,whenreprogrammingprogrammableflagoffsetsettingsmaynotbe
convenient.
Subsequentretransmitoperationsmaybeperformedeachtimetheread
pointerreturningtothe‘marked’location.SeeFigure18,RetransmitfromMark
(FWFTmode)forthe relevanttimingdiagram.
See Figure 9, PartialResetTiming, forthe relevanttimingdiagram.
ASYNCHRONOUS WRITE (ASYW)
MARK
ThewriteportcanbeconfiguredforeitherSynchronousorAsynchronous
mode of operation. If during Master Reset the ASYW input is LOW, then
Asynchronousoperationofthewriteportwillbeselected.DuringAsynchro-
nousoperationofthewriteporttheWCLKinputbecomesWRinput,thisisthe
Asynchronouswritestrobeinput.ArisingedgeonWRwillwritedatapresent
ontheDninputsintotheFIFO.(WENmustbetiedLOWwhenusingthewrite
portinAsynchronous mode).
WhenthewriteportisconfiguredforAsynchronousoperationthefullflag
(FF[1:2]) operates in an asynchronous manner, that is, the full flag will be
updatedbasedinbothawriteoperationandreadoperation.Note,ifAsynchro-
nousmodeisselected,FWFTisnotpermissable.RefertoFigures30,31,34
and35forrelevanttimingandoperationalwaveforms.
TheMARKinputisusedtoselectRetransmitmodeofoperation.AnRCLK
rising edge while MARK is HIGH will mark the memory location of the data
currently present on the output register, the device will also be placed into
retransmitmode.FortheIDT72T36135Maminimumof128words(x36).Also,
once the MARKis set, the write pointerwillnotincrementpastthe “marked”
locationuntiltheMARKisdeasserted.Thisprevents“overwriting”ofretransmit
data.
TheMARKinputmustremainHIGHduringthewholeperiodofretransmit
mode,afallingedgeofRCLKwhileMARKis LOWwilltakethedeviceoutof
retransmitmodeandintonormalmode.AnynumberofMARKlocationscanbe
setduringFIFOoperation,onlythelastmarkedlocationtakingeffect.Oncea
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marklocationhasbeensetthewritepointercannotbeincrementedpastthis READ STROBE & READ CLOCK (RD/RCLK)
markedlocation.Duringretransmitmodewriteoperationstothedevicemay
continuewithouthindrance.
IfSynchronousoperationofthereadporthasbeenselectedviaASYR,this
inputbehavesasRCLK.A readcycleisinitiatedontherisingedgeoftheRCLK
input. Datacanbereadontheoutputs,ontherisingedgeoftheRCLKinput.
ItispermissibletostoptheRCLK. NotethatwhileRCLKisidle,theEF/OR[1:2],
FIRST WORD FALL THROUGH/SERIAL IN (FWFT/SI)
This is a dualpurpose pin. DuringMasterReset, the state ofthe FWFT/ and PAE[1:2] flags will not be updated. The Write and Read Clocks can be
SIinputdetermineswhetherthedevicewilloperateinIDTStandardmodeor independentorcoincident.
First Word Fall Through (FWFT) mode.
IfAsynchronousoperationhasbeenselectedthisinputisRD(ReadStrobe)
If,atthetimeofMasterReset,FWFT/SIisLOW,thenIDTStandardmode .DataisAsynchronouslyreadfromtheFIFOviatheoutputregisterwhenever
willbeselected. ThismodeusestheEmptyFlag(EF[1:2])toindicatewhether there is a rising edge on RD. In this mode the REN and RCS inputs must be
ornotthereareanywordspresentintheFIFOmemory. ItalsousestheFull tiedLOW.TheOEinputisusedtoprovideAsynchronouscontrolofthethree-
Flagfunction(FF[1:2])toindicatewhetherornottheFIFOmemoryhas any stateQnoutputs.
freespaceforwriting. InIDTStandardmode,everywordreadfromtheFIFO,
includingthe first, mustbe requestedusingthe ReadEnable (REN)and WRITE CHIP SELECT (WCS)
RCLK.
The WCS disables all Write Port inputs (data only) if it is held HIGH. To
If,atthetimeofMasterReset,FWFT/SIisHIGH,thenFWFTmodewillbe performnormaloperationsonthewriteport,theWCSmustbeenabled,heldLOW.
selected. ThismodeusesOutputReady(OR[1:2])toindicatewhetherornot
thereis validdataatthedataoutputs (Qn). Italsouses InputReady(IR[1:2]) READ ENABLE (REN)
toindicatewhetherornottheFIFOmemoryhasanyfreespaceforwriting. In
When Read Enable is LOW, data is loaded from the RAM array into the
theFWFTmode,thefirstwordwrittentoanemptyFIFOgoesdirectlytoQnafter outputregisterontherisingedgeofeveryRCLKcycleifthedeviceisnotempty.
threeRCLKrisingedges,REN=LOWis notnecessary. Subsequentwords
must be accessed using the Read Enable (REN) and RCLK.
WhentheRENinputisHIGH,theoutputregisterholdsthepreviousdata
and no new data is loaded into the output register. The data outputs Q0-Qn
AfterMasterReset,FWFT/SIactsasaserialinputforloadingPAE[1:2]and maintainthepreviousdatavalue.
PAF[1:2]offsetsintotheprogrammableregisters. Theserialinputfunctioncan
IntheIDTStandardmode,everywordaccessedatQn,includingthefirst
onlybeusedwhentheserialloadingmethodhasbeenselectedduringMaster wordwrittentoanemptyFIFO, mustbe requestedusingREN providedthat
Reset.SerialprogrammingusingtheFWFT/SIpinfunctionsthesamewayin RCSisLOW. WhenthelastwordhasbeenreadfromtheFIFO,theEmptyFlag
both IDT Standard and FWFT modes.
(EF[1:2])willgoLOW,inhibitingfurtherreadoperations. RENisignoredwhen
the FIFOis empty. Once a write is performed, EF[1:2] willgoHIGHallowing
areadtooccur. TheEF[1:2]flagisupdatedbytwoRCLKcycles+tSKEW after
WRITE STROBE & WRITE CLOCK (WR/WCLK)
IfSynchronousoperationofthewriteporthasbeenselectedviaASYW,this thevalidWCLKcycle.BothRCSandRENmustbeactive,LOWfordatatobe
inputbehavesasWCLK.
read out on the rising edge of RCLK.
AwritecycleisinitiatedontherisingedgeoftheWCLKinput.Datasetup
IntheFWFTmode,thefirstwordwrittentoanemptyFIFOautomaticallygoes
andholdtimesmustbemetwithrespecttotheLOW-to-HIGHtransitionofthe totheoutputsQn,onthethirdvalidLOW-to-HIGHtransitionofRCLK+tSKEW
WCLK.ItispermissibletostoptheWCLK. NotethatwhileWCLKisidle,theFF/ afterthefirstwrite. RENandRCSdonotneedtobeassertedLOW fortheFirst
IR[1:2],andPAF[1:2]flagswillnotbeupdated.TheWriteandReadClockscan Wordtofallthroughtotheoutputregister.Inordertoaccess allotherwords,
eitherbe independentorcoincident.
a read must be executed using REN and RCS. The RCLK LOW-to-HIGH
IfAsynchronousoperationhasbeenselectedthisinputisWR(writestrobe). transition after the last word has been read from the FIFO, Output Ready
DataisAsynchronouslywrittenintotheFIFOviatheDninputswheneverthere (OR[1:2])willgoHIGHwithatrueread(RCLKwithREN=LOW;RCS=LOW),
is arisingedgeonWR.Inthis modetheWENinputmustbetiedLOW.
inhibiting furtherreadoperations. REN is ignoredwhenthe FIFOis empty.
IfAsynchronousoperationoftheReadporthasbeenselected,thenREN
mustbeheldactive,(tiedLOW).
WRITE ENABLE (WEN)
WhentheWENinput isLOW,datamaybeloadedintotheFIFORAMarray
ontherisingedgeofeveryWCLKcycleifthedeviceisnotfull. Dataisstored
in the RAM array sequentially and independently of any ongoing read
operation.
WhenWENisHIGH,nonewdataiswrittenintheRAMarrayoneachWCLK
cycle.
Topreventdataoverflow intheIDTStandardmode,FF[1:2]willgoLOW,
inhibitingfurtherwriteoperations. Uponthecompletionofavalidreadcycle,
FF[1:2]willgoHIGHallowingawritetooccur. TheFF[1:2]isupdatedbytwo
WCLKcycles +tSKEW aftertheRCLKcycle.
SERIAL ENABLE ( SEN )
TheSENinput isanenableusedonlyforserialprogrammingoftheoffset
registers. The serialprogrammingmethodmustbe selectedduringMaster
Reset. SENisalwaysusedinconjunctionwithLD. Whentheselinesareboth
LOW,dataattheSIinputcanbeloadedintotheprogramregisteronebitforeach
LOW-to-HIGHtransitionofSCLK.
When SEN is HIGH, the programmable registers retains the previous
settingsandnooffsetsareloaded. SENfunctionsthesamewayinbothIDT
StandardandFWFTmodes.
Topreventdataoverflow intheFWFTmode, IR[1:2] willgoHIGH,inhibiting
furtherwriteoperations. Uponthecompletionofavalidreadcycle,IR[1:2]will
go LOW allowing a write to occur. The IR[1:2] flag is updated by two WCLK
cycles +tSKEW afterthe validRCLKcycle.
WENisignoredwhentheFIFOisfullineitherFWFTorIDTStandardmode.
IfAsynchronousoperationofthewriteporthasbeenselected,thenWEN
mustbeheldactive,(tiedLOW).
OUTPUT ENABLE ( OE )
WhenOutputEnableisenabled(LOW),theparalleloutputbuffersreceive
datafromtheoutputregister. WhenOEisHIGH,theoutputdatabus(Qn)goes
intoahighimpedancestate.DuringMasteroraPartialResettheOEistheonly
inputthatcanplacetheoutputbusQn,intoHigh-Impedance.DuringResetthe
RCS inputcanbe HIGHorLOW, ithas noeffectonthe Qnoutputs.
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READ CHIP SELECT ( RCS )
registers can be programmed, parallel or serial (see Table 1). After Master
The Read Chip Select input provides synchronous control of the Read Reset, LD enables write operations to and read operations from the offset
outputport. WhenRCSgoesLOW,thenextrisingedgeofRCLKcausesthe registers.Onlytheoffsetloadingmethodcurrentlyselectedcanbeusedtowrite
QnoutputstogototheLow-Impedancestate. WhenRCSgoesHIGH,thenext totheregisters. Offsetregisters canbereadonlyinparallel.
RCLKrisingedgecausestheQnoutputstoreturntoHIGHZ.DuringaMaster
AfterMasterReset,theLDpinisusedtoactivatetheprogrammingprocess
orPartialResettheRCSinputhasnoeffectontheQnoutputbus,OEistheonly oftheflagoffsetvaluesPAE[1:2]andPAF[1:2].PullingLDLOWwillbeginaserial
inputthatprovidesHigh-ImpedancecontroloftheQnoutputs.IfOEisLOWthe loadingorparallelloadorreadoftheseoffsetvalues. THISPINMUSTBEHIGH
QndataoutputswillbeLow-ImpedanceregardlessofRCSuntilthefirstrising AFTERMASTERRESETTOWRITEORREADDATATO/FROMTHEFIFO
edgeofRCLKafteraResetiscomplete.ThenifRCSisHIGHthedataoutputs MEMORY.
willgotoHigh-Impedance.
TheRCSinputdoesnoteffecttheoperationoftheflags. Forexample,when PROGRAMMABLEFLAGMODE(PFM)
thefirstwordiswrittentoanemptyFIFO,theEF[1:2]willstillgofromLOWto
DuringMasterReset,aLOWonPFMwillselectAsynchronousProgram-
HIGHbasedonarisingedgeofRCLK,regardlessofthestateoftheRCSinput. mable flagtimingmode. AHIGHonPFMwillselectSynchronous Program-
Also,whenoperatingtheFIFOinFWFTmodethefirstwordwrittentoan mableflagtimingmode.IfasynchronousPAF/PAE[1:2]configurationisselected
emptyFIFOwillstillbeclockedthroughtotheoutputregisterbasedonRCLK, (PFM,LOWduringMRS),thePAE[1:2]isassertedLOWontheLOW-to-HIGH
regardlessofthestateofRCS.Forthisreasontheusermusttakecarewhen transitionofRCLK.PAE[1:2]isresettoHIGHontheLOW-to-HIGHtransition
adatawordiswrittentoanemptyFIFOinFWFTmode.IfRCSisdisabledwhen of WCLK. Similarly, the PAF[1:2] is asserted LOW on the LOW-to-HIGH
anemptyFIFOiswritteninto,thefirstwordwillfallthroughtotheoutputregister, transitionofWCLKandPAF[1:2]isresettoHIGHontheLOW-to-HIGHtransition
butwillnotbeavailableontheQnoutputswhichareinHIGH-Z.Theusermust ofRCLK.
takeRCSactiveLOWtoaccessthisfirstword,placetheoutputbusinLOW-Z.
IfsynchronousPAE/PAF[1:2]configurationisselected(PFM,HIGHduring
RENmustremaindisabledHIGHforatleastonecycleafterRCShasgoneLOW. MRS),thePAE[1:2]isassertedandupdatedontherisingedgeofRCLKonly
ArisingedgeofRCLKwithRCSandRENactiveLOW,willreadoutthenext andnotWCLK.Similarly,PAF[1:2]isassertedandupdatedontherisingedge
word. Care mustbe takensoas nottolose the firstwordwrittentoanempty ofWCLKonlyandnotRCLK.Themodedesiredisconfiguredduringmaster
FIFOwhenRCSisHIGH.RefertoFigure16,RCSandRENReadOperation resetbythe state ofthe Programmable FlagMode (PFM)pin.
(FWFT Mode). The RCS pin must also be active (LOW) in order to perform
aRetransmit. SeeFigure12forReadCycleandReadChipSelectTiming(IDT
StandardMode). SeeFigure15forReadCycleandReadChipSelectTiming
OUTPUTS:
FULL FLAG ( FF/IR[1:2] )
(First Word Fall Through Mode).
Thisisadualpurposepin. InIDTStandardmode,theFullFlag (FF[1:2])
IfAsynchronousoperationoftheReadporthasbeenselected,thenRCS
functionisselected.WhentheFIFOisfull,FF[1:2]willgoLOW,inhibitingfurther
mustbeheldactive,(tiedLOW).OEprovidesthree-statecontrolofQn.
write operations. WhenFF[1:2] is HIGH, the FIFO is not full. If no reads are
performedafterareset(eitherMRSorPRS),FF[1:2]willgoLOWafterDwrites
WRITE PORT HSTL SELECT (WHSTL)
totheFIFO(D = 524,288fortheIDT72T36135M).SeeFigure10,WriteCycle
Thecontrolinputs,datainputsandflagoutputsassociatedwiththewriteport
andFullFlagTiming(IDTStandardMode),fortherelevanttiminginformation.
canbesetuptobeeitherHSTLorLVTTL.IfWHSTLisHIGHduringtheMaster
PleaseseeFlaggingsectionforexternalgatinginstructionsoftheseflags.
Reset,thenHSTLoperationofthewriteportwillbeselected.IfWHSTLisLOW
InFWFTmode,theInputReady(IR[1:2])functionisselected.IR[1:2]goes
atMasterReset,thenLVTTLwillbeselected.
LOW when memory space is available for writing in data. When there is no
TheinputsandoutputsassociatedwiththewriteportarelistedinTable4,
longeranyfreespaceleft,IR[1:2]goesHIGH,inhibitingfurtherwriteoperations.
I/OConfiguration.
Ifnoreadsareperformedafterareset(eitherMRSorPRS),IR[1:2]willgoHIGH
afterD writestotheFIFO(D = 524,288fortheIDT72T36135M).SeeFigure
READ PORT HSTL SELECT (RHSTL)
13, WriteTiming(FWFTMode),fortherelevanttiminginformation.
Thecontrolinputs,datainputsandflagoutputsassociatedwiththereadport
TheIR[1:2]statusnotonlymeasuresthecontentsoftheFIFOmemory,but
canbesetuptobeeitherHSTLorLVTTL.IfRHSTLisHIGHduringtheMaster
alsocountsthepresenceofawordintheoutputregister. Thus,inFWFTmode,
Reset,thenHSTLoperationofthereadportwillbeselected.IfRHSTLisLOW
the total number of writes necessary to deassertIR[1:2] is one greater than
atMasterReset, thenLVTTLwillbe selectedforthe readport.
needed to assert FF[1:2] in IDT Standard mode.
TheinputsandoutputsassociatedwiththereadportarelistedinTable4,
FF/IR[1:2]issynchronousandupdatedontherisingedgeofWCLK.FF/
I/OConfiguration.
IR[1:2]aredoubleregister-bufferedoutputs.
Note,whenthedeviceisinRetransmitmode,thisflagisacomparisonof
SYSTEM HSTL SELECT (SHSTL)
thewritepointertothe‘marked’location.Thisdiffersfromnormalmodewhere
Allinputsnotassociatedwiththewriteandreadportcanbesetuptobeeither
thisflagisacomparisonofthewritepointertothereadpointer.
HSTLorLVTTL.IfSHSTLisHIGHduringMasterReset,thenHSTLoperation
ofalltheinputsnotassociatedwiththewriteandreadportwillbeselected.If
EMPTY FLAG ( EF/OR[1:2] )
SHSTL is LOW at Master Reset, then LVTTL will be selected. The inputs
This is a dual purpose pin. In the IDT Standard mode, the Empty Flag
associatedwithSHSTLarelistedinTable4,I/OConfiguration.
(EF[1:2])functionisselected. WhentheFIFOisempty,EF[1:2]willgoLOW,
inhibitingfurtherreadoperations. WhenEF[1:2]isHIGH,theFIFOisnotempty.
LOAD (LD)
SeeFigure11,ReadCycle,EmptyFlagandFirstWordLatencyTiming(IDT
Thisisadualpurposepin. DuringMasterReset,thestateoftheLDinput,
Standard Mode), for the relevant timing information. Please see Flagging
alongwithFSEL0andFSEL1,determinesoneofeightdefaultoffsetvaluesfor
sectionforexternalgatinginstructionsoftheseflags.
thePAE[1:2]andPAF[1:2]flags,alongwiththemethodbywhichtheseoffset
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InFWFTmode,theOutputReady(OR[1:2])functionisselected.OR[1:2]
IfasynchronousPAF[1:2]configurationisselected,thePAF[1:2]isasserted
goesLOWatthesametimethatthefirstwordwrittentoanemptyFIFOappears LOWontheLOW-to-HIGHtransitionoftheWriteClock(WCLK). PAF[1:2]is
validontheoutputs. OR[1:2]staysLOWaftertheRCLKLOWtoHIGHtransition reset to HIGH on the LOW-to-HIGH transition of the Read Clock (RCLK). If
thatshiftsthelastwordfromtheFIFOmemorytotheoutputs. OR[1:2]goesHIGH synchronousPAF[1:2]configurationisselected,thePAF[1:2]isupdatedonthe
onlywithatrueread(RCLKwithREN=LOW). Thepreviousdatastaysatthe risingedgeofWCLK. SeeFigure24,AsynchronousAlmost-FullFlagTiming
outputs,indicatingthelastwordwasread. Furtherdatareadsareinhibiteduntil (IDT Standard and FWFT Mode).
OR[1:2]goesLOWagain.SeeFigure14,ReadTiming(FWFTMode),forthe
relevanttiminginformation.
EF/OR[1:2] is synchronous and updated on the rising edge of RCLK.
In IDT Standard mode, EF[1:2] is a double register-buffered output. In
FWFTmode,OR[1:2]isatripleregister-bufferedoutput.
Note,whenthedeviceisinRetransmitmode,thisflagisacomparisonofthe
writepointertothe‘marked’location.Thisdiffersfromnormalmodewherethis
flagis acomparisonofthewritepointertothereadpointer.
PROGRAMMABLE ALMOST-EMPTY FLAG (PAE[1:2])
TheProgrammableAlmost-Emptyflag(PAE[1:2])willgoLOWwhenthe
FIFOreachesthealmost-emptycondition.InIDTStandardmode,PAE[1:2]will
PROGRAMMABLE ALMOST-FULL FLAG ( PAF[1:2] )
TheProgrammableAlmost-Fullflag(PAF[1:2])willgoLOWwhentheFIFO goLOWwhentherearenwordsorlessintheFIFO.Theoffset“n”istheempty
reaches the almost-full condition. In IDT Standard mode, if no reads are offsetvalue.ThedefaultsettingforthisvalueisstatedinthefootnoteofTable 1.
performed after reset (MRS), PAF[1:2] will go LOW after (D - m)words are PleaseseeFlaggingsectionforexternalgatinginstructionsoftheseflags.
writtentotheFIFO.ThePAF[1:2]willgoLOWafter(524,288-m)writesforthe
In FWFT mode, the PAE[1:2] will go LOW when there are n+1 words or
IDT72T36135M.Theoffset“m”isthefulloffsetvalue.Thedefaultsettingforthis less intheFIFO.Thedefaultsettingforthis valueis statedinTable1.
valueisstatedinthefootnoteofTable2,StatusFlagsforIDTStandardMode.
PleaseseeFlaggingsectionforexternalgatinginstructionsoftheseflags.
InFWFTmode,thePAF[1:2]willgoLOWafter(524,289-m)writesforthe
SeeFigure23, Synchronous ProgrammableAlmost-EmptyFlagTiming
(IDTStandardandFWFTMode), forthe relevanttiminginformation.
IfasynchronousPAE[1:2]configurationisselected,thePAE[1:2]isasserted
IDT72T36135M,wheremisthefulloffsetvalue.Thedefaultsettingforthisvalue LOWontheLOW-to-HIGHtransitionoftheReadClock(RCLK). PAE[1:2]is
is statedinTable 3, Status Flags forFWFTMode. resettoHIGHonthe LOW-to-HIGHtransitionofthe Write Clock(WCLK). If
SeeFigure22,SynchronousProgrammableAlmost-FullFlagTiming(IDT synchronousPAE[1:2]configurationisselected,thePAE[1:2]isupdatedonthe
StandardandFWFTMode),fortherelevanttiminginformation.
risingedgeofRCLK. SeeFigure25,AsynchronousProgrammableAlmost-
Empty Flag Timing (IDT Standard and FWFT Mode).
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CONSIDERATIONS FOR READING FLAG OUTPUTS
gateisusedforFWFTmodeandanANDgateisusedforIDTmode. Thismust
Onthisdevice,therearetwosetsofflaggingoutputsfortheemptyflag(EF1 bedonetoavoidtimingskewproblemsbetweenthetwosetsofflags.Forthe
& EF2), full flag (FF1 & FF2), Programmable Almost Empty Flag (PAE1 & PAE[1:2]andPAF[1:2]activelowoutputflags,theuserhastheoptiontoleave
PAE2),andProgrammableAlmostFullFlag(PAF1&PAF2)theusermustwork thePAE[1:2]andPAF[1:2]asisandusebothpinsatdifferentprogrammable
withinordertobeabletocorrectlyreadthestatusofeachflag. Sincethisdevice watermarks formeasuringbufferstatus. Please see the sectiononParallel
isamulti-chipmodule(MCM),bothdie’sflagsmustbereadaccordinglytoavoid ProgrammingModetounderstandhowtoprogramthesetwosetsofflagsas
skewingproblemsbetweenthetwointernaldie.
differentwatermarksinFunctionalDescriptionsectionofthedatasheet. This
Toremedythis function,theusermusttietogetherFF1 &FF2,andEF1& givesaddedflexibilityforqueuemanagement.Belowisanexamplediagram
EF2flagoutputstoanexternalgatefromaneighboringprogrammabledevice forhowthisisaccomplished.
suchasanFPGAorPLDandreadfromtheoutputofthelogicalgate. AnOR
IDT72T36135M
EF1
EF2
FF1
FF2
PAE1
PAE2
PAF1
PAF2
OPTIONAL
GATE
(1)
GATE
(1)
AND
GATE
AND
GATE
EF
FF
PAE
PAF
6723 drw10
NOTE:
1. An “OR” Gate is used for FWFT mode, and an “AND” Gate is used for IDT Standard mode.
Figure 4. Output Flag Gating Considerations
interspersedparity. Fromthesechanges,the18MFIFOhasremovedspecific
PINCOMPATIBILITYWITH9MTERASYNC(IDT72T36125)CONSIDER-
ATIONS
inputssuchasIW,OW,BM,BE,IP,whilealsogaininganothersetofoutputflags
as specified in Considerations for Reading Flag Outputs which are EF2,
FF2, PAE2, and PAF2.
Tomaintaindrop-inreplacementcompatibilityforthe18MTeraSync,thepin
changesonthepindiagramforthe18MTeraSyncFIFOfromthe9MTeraSync
FIFOhave beenidentified, andlistedinthe table below.
TheIDT72T36135Mcanbeadropandreplacementforthe9MTeraSync
(IDT72T36125)ifspecificpinchangesaremadetothe18MFIFO. Sincethe
18MTeraSyncisaMulti-ChipModule(MCM),containingtwo9MTeraSyncs
(IDT72T18125) in width expansion mode, certain functionality can not be
offered in the 18M TeraSync such as bus matching, single flag outputs and
TABLE 5 — PIN CHANGES BETWEEN 9M TERASYNC AND 18M TERASYNC
9M TeraSync FIFO (IDT72T36125)
18M TeraSync FIFO (IDT72T36135M)
pins changed
new pins
BM
IP
EF2
PAE2
IW
NC (No Connect)
NC (No Connect)
PAF2
OW
HF
EREN
ERCLK
BE
FF2
NC (No Connect)
GND
NOTES:
1. Internally, the 9M pins on the left side of the table will be tied to the GND or VDD plane, respectively in the 18M device.
2. Please see IDT72T36125 TeraSync FIFO datasheet for additional features listed.
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JTAG signaling must be provided serially to each array and utilize the
information provided in the Scan Register Descriptions, JTATG Instruction
Description.Specifically,commandsforArrayBmustprecedethoseArrayA
in any JTAG operations sent to the IDT72T36135M. Please reference
Application Note AN-411, “JTAG Testing of Multichip Modules” for specific
instructions on performing JTAG testing on the IDT72T36135M. AN-411 is
availableatwww.idt.com.
JTAG FUNCTIONALITY AND CON-
FIGURATION
TheIDT72T36135Miscomposedoftwoindependentmemoryarrays,and
thuscannotbetreatedasasingleJTAGdeviceinthescanchain.Thetwoarrays
(AandB)eachhaveidenticalcharacteristicsandcommandsbutmustbetreated
as separate entities in JTAG operations. Please refer to Figure 5, JTAG
Configuration for IDT72T36135M.
TDI
TDOA
TDIB
TDO
Array A
Array B
TCK
TMS
TRST
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Figure 5. JTAG Configuration for IDT72T36135M
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JTAGTIMINGSPECIFICATION
tTCK
t4
t1
t2
TCK
t3
TDI/
TMS
tDS
tDH
TDO
TDO
tDO
t6
TRST
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Notes to diagram:
t1 = tTCKLOW
t2 = tTCKHIGH
t5
t3 = tTCKFALL
t4 = tTCKRISE
t5 = tRST (reset pulse width)
t6 = tRSR (reset recovery)
JTAG
ACELECTRICALCHARACTERISTICS
(vcc = 2.5V 5%; Tcase = 0°C to +85°C)
Parameter
Symbol
Test
IDT72T36135M
Conditions
Min. Max. Units
SYSTEMINTERFACEPARAMETERS
JTAGClockInputPeriod tTCK
-
-
-
-
-
-
-
100
40
40
-
-
-
ns
ns
ns
ns
ns
ns
ns
JTAGClockHIGH
JTAGClockLow
tTCKHIGH
IDT72T36135M
tTCKLOW
tTCKRISE
tTCKFALL
tRST
-
Parameter
Symbol Test Conditions Min. Max. Units
JTAGClockRiseTime
JTAGClockFallTime
JTAGReset
5(1)
5(1)
-
(1)
DataOutput
tDO
-
20
-
ns
ns
ns
(1)
-
DataOutputHold tDOH
0
50
50
DataInput
tDS
tDH
trise=3ns
tfall=3ns
10
10
-
-
JTAG Reset Recovery
tRSR
-
NOTE:
1. 50pf loading on external output signals.
NOTE:
1. Guaranteed by design.
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•
•
•
TAPcontroller
Instruction Register (IR)
Data Register Port (DR)
JTAGINTERFACE
Five additional pins (TDI, TDO, TMS, TCK and TRST) are provided to
supporttheJTAGboundaryscaninterface.TheIDT72T36135Mincorporates
thenecessarytapcontrollerandmodifiedpadcellstoimplementtheJTAG facility.
NotethatIDTprovidesappropriateBoundaryScanDescriptionLanguage
programfilesforthesedevices.
Thefollowingsectionsprovideabriefdescriptionofeachelement. Fora
completedescriptionrefertotheIEEEStandardTestAccessPortSpecification
(IEEEStd. 1149.1-1990).
TheStandardJTAGinterfaceconsistsoffourbasicelements:
The Figure belowshows the standardBoundary-ScanArchitecture
•
Test Access Port (TAP)
Mux
DeviceID Reg.
Boundary Scan Reg.
Bypass Reg.
TDO
TDI
T
A
P
clkDR, ShiftDR
UpdateDR
TMS
TAP
TCLK
Cont-
roller
TRST
Instruction Decode
clklR, ShiftlR
UpdatelR
Instruction Register
Control Signals
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Figure 6. Boundary Scan Architecture
THETAPCONTROLLER
TEST ACCESS PORT (TAP)
TheTapcontrollerisasynchronousfinitestatemachinethatrespondsto
TMSandTCLKsignalstogenerateclockandcontrolsignalstotheInstruction
andDataRegisters forcaptureandupdateofdata.
The Tap interface is a general-purpose port that provides access to the
internaloftheprocessor. Itconsistsoffourinputports(TCLK,TMS,TDI,TRST)
and one output port (TDO).
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1
Test-Logic
Reset
0
1
0
1
1
Run-Test/
Idle
Select-
DR-Scan
Select-
IR-Scan
0
0
1
1
Capture-DR
Capture-IR
0
0
0
0
Shift-IR
Shift-DR
1
1
1
1
Input = TMS
Exit1-IR
Exit1-DR
0
0
0
0
Pause-IR
Pause-DR
1
1
Exit2-IR
Exit2-DR
0
0
1
1
Update-IR
Update-DR
1
0
1
0
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NOTES:
1. Five consecutive TCK cycles with TMS = 1 will reset the TAP.
2. TAP controller does not automatically reset upon power-up. The user must provide a reset to the TAP controller (either by TRST or TMS).
3. TAP controller must be reset before normal FIFO operations can begin.
Figure 7. TAP Controller State Diagram
Capture-IRInthiscontrollerstate,theshiftregisterbankintheInstruction
RegisterparallelloadsapatternoffixedvaluesontherisingedgeofTCK.The
lasttwosignificantbits arealways requiredtobe“01”.
Shift-IR In this controller state, the instruction register gets connected
betweenTDIandTDO,andthecapturedpatterngetsshiftedoneachrisingedge
ofTCK.TheinstructionavailableontheTDIpinisalsoshiftedintotheinstruction
register.
Exit1-IRThisisacontrollerstatewhereadecisiontoentereitherthePause-
IRstateorUpdate-IRstateismade.
Pause-IRThis state is providedinordertoallowthe shiftingofinstruction
registertobetemporarilyhalted.
Exit2-DRThisisacontrollerstatewhereadecisiontoentereithertheShift-
IRstateorUpdate-IRstateismade.
Update-IRInthiscontrollerstate,theinstructionintheinstructionregisteris
latchedintothelatchbankoftheInstructionRegisteroneveryfallingedgeof
TCK.Thisinstructionalsobecomesthecurrentinstructiononceitislatched.
Capture-DRInthiscontrollerstate,thedataisparallelloadedintothedata
registersselectedbythecurrentinstructionontherisingedgeofTCK.
Shift-DR, Exit1-DR, Pause-DR, Exit2-DR and Update-DR These
controllerstates are similartothe Shift-IR, Exit1-IR, Pause-IR, Exit2-IRand
Update-IRstatesintheInstructionpath.
Refer to the IEEE Standard Test Access Port Specification (IEEE Std.
1149.1)forthefullstatediagram
AllstatetransitionswithintheTAPcontrolleroccurattherisingedgeofthe
TCLKpulse. TheTMSsignallevel(0or1)determinesthestateprogression
thatoccursoneachTCLKrisingedge.TheTAPcontrollertakesprecedence
overtheFIFOmemoryandmustberesetafterpowerupofthedevice. See
TRSTdescriptionformoredetails onTAPcontrollerreset.
Test-Logic-ResetAlltestlogicisdisabledinthiscontrollerstateenablingthe
normaloperationoftheIC.TheTAPcontrollerstatemachineisdesignedinsuch
awaythat,nomatterwhattheinitialstateofthecontrolleris,theTest-Logic-Reset
statecanbeenteredbyholdingTMSathighandpulsingTCKfivetimes.This
is the reason why the Test Reset (TRST) pin is optional.
Run-Test-IdleInthiscontrollerstate,thetestlogicintheICisactiveonlyif
certaininstructionsarepresent.Forexample,ifaninstructionactivatestheself
test,thenitwillbeexecutedwhenthecontrollerentersthisstate.Thetestlogic
intheICis idles otherwise.
Select-DR-ScanThis is a controllerstate where the decisiontoenterthe
DataPathortheSelect-IR-Scanstateismade.
Select-IR-Scan This is a controller state where the decision to enter the
InstructionPathismade.TheControllercanreturntotheTest-Logic-Resetstate
otherwise.
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JTAG INSTRUCTION REGISTER
SCANREGISTERDESCRIPTIONS
TheInstructionregisterallowsinstructiontobeseriallyinputintothedevice
whentheTAPcontrollerisintheShift-IRstate. Theinstructionisdecodedto
performthefollowing:
THE INSTRUCTION REGISTER
TheInstructionregisterallowsaninstructiontobeshiftedinseriallyintothe
processor at the rising edge of TCLK.
TheInstructionis usedtoselectthetesttobeperformed,orthetestdata
registertobeaccessed,orboth. Theinstructionshiftedintotheregisterislatched
atthecompletionoftheshiftingprocesswhentheTAPcontrollerisatUpdate-
IRstate.
Theinstructionregistermustcontain8bitinstructionregister-basedcells
whichcanholdinstructiondata. Thesemandatorycellsarelocatednearestthe
serialoutputstheyaretheleastsignificantbits.
•
Selecttestdataregistersthatmayoperatewhiletheinstructionis
current. Theothertestdataregistersshouldnotinterferewithchip
operationandtheselecteddataregister.
Definetheserialtestdataregisterpaththatisusedtoshiftdatabetween
TDI and TDO during data register scanning.
•
The Instruction Register is a 8 bit field (i.e.IR3, IR2, IR1, IR0 per die) to
decode32differentpossibleinstructions. Instructionsaredecodedasfollows.
Please note:
Again,sincethisdeviceisatwodieMCM,theJTAGinstructionsmustbeshifted
intwiceduringJTAGtesting.Toaccountforeachdies4bitinstructionregisters
foratotalof8bitsaltogether.
TESTDATAREGISTER
TheTestDataregistercontainsthreetestdataregisters:theBypass,the
Boundary Scan register and Device ID register.
Theseregistersareconnectedinparallelbetweenacommonserialinput
andacommonserialdataoutput.
Thefollowingsectionsprovideabriefdescriptionofeachelement. Fora
completedescription,refertotheIEEEStandardTestAccessPortSpecification
(IEEEStd. 1149.1-1990).
JTAGINSTRUCTIONDESCRIPTION
Hex
Instruction
Function
Value
0x00
0x22
0x11
0x33
0xFF
EXTEST
IDCODE
SAMPLE/PRELOAD
HIGH-IMPEDANCE
BYPASS
SelectBoundaryScanRegister
SelectChipIdentificationdataregister
SelectBoundaryScanRegister
JTAG
TEST BYPASS REGISTER
SelectBypassRegister
TheregisterisusedtoallowtestdatatoflowthroughthedevicefromTDI
toTDO. Itcontainsasinglestageshiftregisterforaminimumlengthinserialpath.
Whenthebypassregisterisselectedbyaninstruction,theshiftregisterstage
is settoa logiczeroonthe risingedge ofTCLKwhenthe TAPcontrolleris in
theCapture-DRstate.
JTAG Instruction Register Decoding
Thefollowingsectionsprovideabriefdescriptionofeachinstruction. For
acompletedescriptionrefertotheIEEEStandardTestAccessPortSpecification
(IEEEStd. 1149.1-1990).
The operation of the bypass register should not have any effect on the
operationofthedeviceinresponsetotheBYPASSinstruction.
EXTEST
TherequiredEXTESTinstructionplacestheICintoanexternalboundary-
testmodeandselectstheboundary-scanregistertobeconnectedbetweenTDI
andTDO. Duringthis instruction, theboundary-scanregisteris accessedto
drivetestdataoff-chipviatheboundaryoutputsandreceivetestdataoff-chip
viatheboundaryinputs.Assuch,theEXTESTinstructionistheworkhorseof
IEEE.Std1149.1,providingforprobe-lesstestingofsolder-jointopens/shorts
andoflogicclusterfunction.
THE BOUNDARY-SCAN REGISTER
TheBoundaryScanRegisterallowsserialdataTDIbeloadedintoorread
outoftheprocessorinput/outputports. TheBoundaryScanRegisterisapart
oftheIEEE1149.1-1990StandardJTAGImplementation.
THE DEVICE IDENTIFICATION REGISTER
The Device IdentificationRegisteris a ReadOnly64-bitregisterusedto
specify the manufacturer, part number and version of the processor to be
determinedthroughtheTAPinresponsetotheIDCODEinstruction.
IDT JEDEC ID number is 0xB3. This translates to 0x33 when the parity
is droppedinthe11-bitManufacturerIDfield.
IDCODE
TheoptionalIDCODEinstructionallowstheICtoremaininitsfunctionalmode
andselectstheoptionaldeviceidentificationregistertobeconnectedbetween
TDIandTDO.Thedeviceidentificationregisterisa64-bitshiftregistercontaining
information regarding the IC manufacturer, device type, and version code.
Accessingthedeviceidentificationregisterdoesnotinterferewiththeoperation
oftheIC.Also,accesstothedeviceidentificationregistershouldbeimmediately
available,viaaTAPdata-scanoperation,afterpower-upoftheICorafterthe
TAPhasbeenresetusingtheoptionalTRSTpinorbyotherwisemovingtothe
Test-Logic-Resetstate.
For the IDT72T36135M, the Part Number field contains the following
values:
Device
IDT72T36135M
Part# Field
0417
31(MSB)
28 27
12 11
1 0(LSB)
Version (4 bits) Part Number (16-bit) Manufacturer ID (11-bit)
0X0
0X33
1
SAMPLE/PRELOAD
TherequiredSAMPLE/PRELOADinstructionallows theICtoremainina
normalfunctionalmodeandselectstheboundary-scanregistertobeconnected
betweenTDIandTDO.Duringthisinstruction,theboundary-scanregistercan
beaccessedviaadatescanoperation,totakeasampleofthefunctionaldata
enteringandleavingtheIC.Thisinstructionisalsousedtopreloadtestdatainto
theboundary-scanregisterbeforeloadinganEXTESTinstruction.
IDT72T36135MJTAGDevice Identification Register
Please note:
The IDT72T36135Mdevice is a twodie MCMwhichmeans 64bits willbe
shiftedoutofthedevicewhentheuserisinIDCODE.SincetheJTAGdevice
identificationregisteris32bitsperdie.
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BYPASS
HIGH-IMPEDANCE
The required BYPASS instruction allows the IC to remain in a normal
functional mode and selects the one-bit bypass register to be connected
betweenTDIandTDO.TheBYPASSinstructionallowsserialdatatobetransferred
throughtheICfromTDItoTDOwithoutaffectingtheoperationoftheIC.
TheoptionalHigh-Impedanceinstructionsetsalloutputs(includingtwo-state
aswellasthree-statetypes)ofanICtoadisabled(high-impedance)stateand
selects the one-bit bypass register to be connected between TDI and TDO.
Duringthisinstruction,datacanbeshiftedthroughthebypassregisterfromTDI
toTDOwithoutaffectingtheconditionoftheICoutputs.
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
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™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
tRS
MRS
t
RSR
RSR
t
RSS
RSS
REN
WEN
t
t
tRSS
tRSR
FWFT/SI
tRSS
tRSR
LD
tRSS
FSEL0,
FSEL1
t
t
t
HRSS
WHSTL
RHSTL
SHSTL
HRSS
HRSS
tRSS
PFM
tRSS
RT
tRSS
SEN
tRSF
If FWFT = HIGH, OR = HIGH
If FWFT = LOW, EF = LOW
EF/OR[1:2]
tRSF
If FWFT = LOW, FF = HIGH
If FWFT = HIGH, IR = LOW
FF/IR[1:2]
t
RSF
RSF
PAE[1:2]
PAF[1:2]
t
tRSF
OE = HIGH
OE = LOW
Q0 - Qn
6723 drw15
NOTE:
1. During Master Reset the High-Impedance control of the Qn data outputs is provided by OE only, RCS can be HIGH or LOW until the first rising edge of RCLK
after Master Reset is complete.
Figure 8. Master Reset Timing
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
tRS
PRS
tRSS
tRSR
REN
tRSS
tRSR
WEN
RT
tRSS
tRSS
SEN
If FWFT = HIGH, OR = HIGH
If FWFT = LOW, EF = LOW
If FWFT = LOW, FF = HIGH
If FWFT = HIGH, IR = LOW
t
RSF
EF/OR
[1:2]
tRSF
FF/IR
[1:2]
tRSF
PAE
[1:2]
tRSF
PAF
[1:2]
tRSF
OE = HIGH
OE = LOW
Q0 - Qn
6723 drw16
NOTE:
1. During Partial Reset the High-Impedance control of the Qn data outputs is provided by OE only, RCS can be HIGH or LOW until the first rising edge
of RCLK after Master Reset is complete.
Figure 9. Partial Reset Timing
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IDT72T36135M 2.5V 18M-BIT TeraSync
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™
36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
t
CLK
tCLKH
t
CLK
NO WRITE
NO WRITE
L
WCLK
2
1
(1)
1
(1)
2
t
SKEW1
tDH
t
SKEW1
tDS
tDH
tDS
D
X+1
DX
D0 - Dn
tWFF
tWFF
tWFF
tWFF
FF[1:2]
WEN
RCLK
tENS
tENS
tENS
tENH
tENH
REN
RCS
tA
tA
Q0 - Qn
NEXT DATA READ
DATA READ
6723 drw17
tRCSLZ
NOTES:
1. tSKEW1 is the minimum time between a rising RCLK edge and a rising WCLK edge to guarantee that FF[1:2] will go HIGH (after one WCLK cycle pus tWFF). If the time between
the rising edge of the RCLK and the rising edge of the WCLK is less than tSKEW1, then the FF[1:2] deassertion may be delayed one extra WCLK cycle.
2. LD = HIGH, OE = LOW, EF[1:2] = HIGH.
3. WCS = LOW.
Figure 10. Write Cycle and Full Flag Timing (IDT Standard Mode)
tCLK
tCLKH
tCLKL
1
2
RCLK
REN
tENH
tENS
tENS
tENH
tENH
tENS
NO OPERATION
NO OPERATION
tREF
tREF
tREF
EF[1:2]
Q0 - Qn
tA
t
A
tA
D0
LAST WORD
D1
LAST WORD
t
OLZ
tOHZ
tOLZ
t
OE
OE
WCLK
WEN
(1)
SKEW1
t
tENS
tENH
tENH
tENS
tWCSS
tWCSH
WCS
tDS
tDH
tDH
tDS
D0
D1
D0 - Dn
6723 drw18
NOTES:
1. tSKEW1 is the minimum time between a rising WCLK edge and a rising RCLK edge to guarantee that EF[1:2] will go HIGH (after one RCLK cycle plus tREF). If the time between
the rising edge of WCLK and the rising edge of RCLK is less than tSKEW1, then EF[1:2] deassertion may be delayed one extra RCLK cycle.
2. LD = HIGH.
3. First data word latency = tSKEW1 + 1*TRCLK + tREF.
4. RCS is LOW.
Figure 11. Read Cycle, Output Enable, Empty Flag and First Data Word Latency (IDT Standard Mode)
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IDT72T36135M 2.5V 18M-BIT TeraSync
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™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
2
1
RCLK
tENS
REN
RCS
tENS
tENS
tENS
tENH
tREF
tREF
EF[1:2]
tRCSHZ
t
RCSH
Z
tA
tA
tRCSLZ
tRCSLZ
LAST DATA-1
LAST DATA
Q0 - Qn
t
SKEW1(1)
WCLK
tENS
tENH
WEN
tDS
tDH
Dn
Dx
6723 drw19
NOTES:
1. tSKEW1 is the minimum time between a rising WCLK edge and a rising RCLK edge to guarantee that EF[1:2] will go HIGH (after one RCLK cycle plus tREF). If the time between
the rising edge of WCLK and the rising edge of RCLK is less than tSKEW1, then EF[1:2] deassertion may be delayed one extra RCLK cycle.
2. LD = HIGH.
3. First data word latency = tSKEW1 + 1*TRCLK + tREF.
4. OE is LOW.
Figure 12. Read Cycle and Read Chip Select (IDT Standard Mode)
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FEBRUARY04,2009
34
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FEBRUARY04,2009
35
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
RNE
ERN RNE
REN ERN
RSC
CRS RSC
RCS CRS
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IDT72T36135M 2.5V 18M-BIT TeraSync
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™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FEBRUARY04,2009
38
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
FEBRUARY04,2009
39
IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™
36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
t
SCLK
tSCKH
t
SCKL
SCLK
tSENH
tSENS
tENH
SEN
LD
tLDS
tLDS
tLDH
tSDH
tSDS
BIT 19
BIT 19
BIT 1
BIT 1
SI
6723 drw26
FULL OFFSET
EMPTY OFFSET
Figure 19. Serial Loading of Programmable Flag Registers (IDT Standard and FWFT Modes)
tCLK
tCLKH
tCLKL
WCLK
LD
tLDH
tLDS
tLDH
tENH
tENS
tENH
WEN
tDS
tDH
tDH
PAF
OFFSET
PAE
OFFSET
D0 - Dn
6723 drw27
Figure 20. Parallel Loading of Programmable Flag Registers (IDT Standard and FWFT Modes)
tCLK
tCLKH
tCLKL
RCLK
tLDH
tLDH
tLDH
tLDS
tLDS
tLDS
LD
tENH
tENH
tENH
tENS
tENS
tENS
REN
t
A
t
A
tA
DATA IN OUTPUT REGISTER
PAE OFFSET VALUE
PAF OFFSET VALUE
PAE OFFSET
Q0 - Qn
6723 drw28
NOTES:
1. OE = LOW.
2. The offset registers cannot be read on consecutive RCLK cycles. The read must be disabled (REN = HIGH) for a minimum of one RCLK cycle in between register accesses.
Figure 21. Parallel Read of Programmable Flag Registers (IDT Standard and FWFT Modes)
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™
36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
tCLKL
tCLKL
WCLK
1
2
2
1
tENS
tENH
WEN
tPAFS
tPAFS
D - m words in FIFO(2)
D-(m+1) words
in FIFO(2)
D - (m +1) words in FIFO(2)
PAF
[1:2]
t
SKEW2(3)
RCLK
tENH
tENS
6723 drw29
REN
NOTES:
1. m = PAF[1:2] offset.
2. D = maximum FIFO depth.
In IDT Standard mode: D = 524,288 for the IDT72T36135M.
In FWFT mode: D = 524,289 for the IDT72T36135M.
3. tSKEW2 is the minimum time between a rising RCLK edge and a rising WCLK edge to guarantee that PAF[1:2] will go HIGH (after one WCLK cycle plus tPAFS). If the time between
the rising edge of RCLK and the rising edge of WCLK is less than tSKEW2, then the PAF[1:2] deassertion time may be delayed one extra WCLK cycle.
4. PAF[1:2] is asserted and updated on the rising edge of WCLK only.
5. Select this mode by setting PFM HIGH during Master Reset.
Figure 22. Synchronous Programmable Almost-Full Flag Timing (IDT Standard and FWFT Modes)
tCLKH
tCLKL
WCLK
tENS
tENH
WEN
n words in FIFO(2)
n + 1 words in FIFO(3)
,
n
words in FIFO(2)
n + 1 words in FIFO(3)
SKEW2(4)
,
n + 1 words in FIFO(2)
n + 2 words in FIFO(3)
,
PAE
[1:2]
tPAES
tPAES
t
1
2
1
2
RCLK
tENS
tENH
6723 drw30
REN
NOTES:
1. n = PAE[1:2] offset.
2. For IDT Standard mode
3. For FWFT mode.
4. tSKEW2 is the minimum time between a rising WCLK edge and a rising RCLK edge to guarantee that PAE[1:2] will go HIGH (after one RCLK cycle plus tPAES). If the time between
the rising edge of WCLK and the rising edge of RCLK is less than tSKEW2, then the PAE[1:2] deassertion may be delayed one extra RCLK cycle.
5. PAE[1:2] is asserted and updated on the rising edge of WCLK only.
6. Select this mode by setting PFM HIGH during Master Reset.
7. RCS = LOW.
Figure 23. Synchronous Programmable Almost-Empty Flag Timing (IDT Standard and FWFT Modes)
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
tCLKH
tCLKL
WCLK
tENS
tENH
WEN
tPAFA
D - m words
in FIFO
D - (m + 1) words
in FIFO
D - (m + 1) words in FIFO
PAF[1:2]
RCLK
REN
tPAFA
tENS
6723 drw31
NOTES:
1. m = PAF[1:2] offset.
2. D = maximum FIFO Depth.
In IDT Standard Mode: D = 524,288 for the IDT72T36135M.
In FWFT Mode: D = 524,289 for the IDT72T36135M.
3. PAF[1:2] is asserted to LOW on WCLK transition and reset to HIGH on RCLK transition.
4. Select this mode by setting PFM LOW during Master Reset.
5. RCS = LOW.
Figure 24. Asynchronous Programmable Almost-Full Flag Timing (IDT Standard and FWFT Modes)
tCLKH
tCLKL
WCLK
tENS
tENH
WEN
(2)
tPAEA
(2)
n words in FIFO
,
n words in FIFO
,
(2)
n + 1 words in FIFO
n + 2 words in FIFO
,
(3)
PAE[1:2]
RCLK
REN
(3)
n + 1 words in FIFO
n + 1 words in FIFO
(3)
t
PAE
A
tENS
6723 drw22
NOTES:
1. n = PAE[1:2] offset.
2. For IDT Standard Mode.
3. For FWFT Mode.
4. PAE[1:2] is asserted LOW on RCLK transition and reset to HIGH on WCLK transition.
5. Select this mode by setting PFM LOW during Master Reset.
6. RCS = LOW.
Figure 25. Asynchronous Programmable Almost-Empty Flag Timing (IDT Standard and FWFT Modes)
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
RCLK
tENS
tENH
tA
REN
Qn
FF[1:2]
WR
W0
W1
tFFA
tFFA
tFFA
tCYH
tCYC
tDS
tDH
WD
Dn
WD+1
6723 drw23
NOTE:
1. OE = LOW, WEN = LOW and RCS = LOW.
Figure 26. Asynchronous Write, Synchronous Read, Full Flag Operation (IDT Standard Mode)
1
2
RCLK
tENS
tEN
H
REN
tA
tA
Last Word
W1
W0
Qn
tREF
tREF
EF[1:2]
tCYL
tSKEW
tCYH
WR
tCYC
tDH
tDH
tDS
tDS
W0
W1
Dn
6723 drw34
NOTE:
1. OE = LOW, WEN = LOW and RCS = LOW.
Figure 27. Asynchronous Write, Synchronous Read, Empty Flag Operation (IDT Standard Mode)
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
No Write
1
WCLK
WEN
Dn
2
DF+1
DF
tWFF
tWFF
FF[1:2]
tCYC
tSKEW
tCYL
tCYH
RD
tAA
tAA
Qn
Last Word
WX
WX+1
6723 drw35
NOTE:
1. OE = LOW, RCS = LOW and REN = LOW.
2. Asynchronous Read is available in IDT Standard Mode only.
Figure 28. Synchronous Write, Asynchronous Read, Full Flag Operation (IDT Standard Mode)
WCLK
WEN
Dn
tENS
tDS
tENH
tDH
W0
tEFA
EF[1:2]
tEFA
tRPE
RD
tCYH
tAA
Qn
Last Word in Output Register
W0
6723 drw36
NOTE:
1. OE = LOW, REN = LOW and RCS = LOW.
2. Asynchronous Read is available in IDT Standard Mode only.
Figure 29. Synchronous Write, Asynchronous Read, Empty Flag Operation (IDT Standard Mode)
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
524,288 x 36
™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
tCYC
tCYH
tCY
L
WR
Dn
tDH
tDH
tDS
W
0
W1
RD
Qn
tAA
tAA
W
1
W
0
Last Word in O/P Register
tRPE
tEFA
tEFA
EF[1:2]
6723 drw37
NOTES:
1. OE = LOW, WEN = LOW, REN = LOW and RCS = LOW
2. Asynchronous Read is available in IDT Standard Mode only.
Figure 30. Asynchronous Write, Asynchronous Read, Empty Flag Operation (IDT Standard Mode)
tCYC
tCYH
tCYL
WR
Dn
tDH
t
DH
tDS
tDS
W
y+1
Wy
tCYC
tCYH
tCYL
RD
Qn
tAA
tAA
Wx
Wx+1
Wx+2
tFFA
tFFA
FF[1:2]
6723 drw38
NOTES:
1. OE = LOW, WEN = LOW, REN = LOW and RCS = LOW.
2. Asynchronous Read is available in IDT Standard Mode only.
Figure 31. Asynchronous Write, Asynchronous Read, Full Flag Operation (IDT Standard Mode)
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
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™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
flagsshouldbegatedusinglogicalgatestoremovethepossibilityofclockskew
betweenthetwodevice(s)outputs.
Figure 32 demonstrates a width expansion using two IDT72T36135M
devices. D0 -D35 fromeachdevice forma 72-bitwide inputbus andQ0-Q35
fromeachdeviceforma72-bitwideoutputbus.Anywordwidthcanbeattained
byaddingadditionalIDT72T36135Mdevices.
OPTIONALCONFIGURATIONS
WIDTH EXPANSION CONFIGURATION
Wordwidthmaybeincreasedbyconnectingtogetherthecontrolsignalsof
multipledevicesplususingexternalgatinglogic.Statusflagscanbegatedand
detectedfromthegateoutput.TheEF[1:2],FF[1:2],PAE[1:2],andPAF[1:2]
FULL FLAG/INPUT READY
PROGRAMMABLE ALMOST FULL
FIFO#1
FIFO#1
SERIAL CLOCK
(SCLK)
AND
GATE
GATE
(1)
(PAF)
(FF/IR)
GATE
(1)
AND
GATE
PARTIAL RESET (PRS)
GATE
(1)
FIFO#2
AND
FIFO#2
GATE
MASTER RESET (MRS)
FIRST WORD FALL THROUGH/
SERIAL INPUT (FWFT/SI)
FIFO#1
FIFO#1
AND
GATE
GATE
(1)
(PAE)
AND
(EF/OR)
GATE
(1)
GATE
RETRANSMIT (RT)
FIFO#2
AND
GATE
FIFO#2
GATE
(1)
D
m+1 - D
n
EMPTY FLAG/OUTPUT READY
PROGRAMMABLE ALMOST
EMPTY
m + n
m
n
D0 - Dm
DATA IN
READ CLOCK (RCLK)
READ CHIP SELECT (RCS)
WRITE CLOCK (WCLK)
WRITE ENABLE (WEN)
LOAD (LD)
READ ENABLE (REN)
OUTPUT ENABLE (OE)
FULL FLAG/INPUT READY (FF/IR) #1
FULL FLAG/INPUT READY (FF/IR)) #2
GATE
(1)
#1
FULL FLAG/INPUT READY (FF/IR)
GATE
(1)
IDT
72T36135M
IDT
72T36135M
FULL FLAG/INPUT READY (FF/IR) #2
PROGRAMMABLE ALMOST FULL (PAF) #1
PROGRAMMABLE ALMOST FULL (PAF) #2
AND
GATE
FIFO
#2
FIFO
#1
PROGRAMMABLE ALMOST FULL (PAF) #1
PROGRAMMABLE ALMOST FULL (PAF) #2
AND
GATE
EMPTY FLAG/OUTPUT READY (EF/OR) #1
EMPTY FLAG/OUTPUT READY (EF/OR) #2
GATE
(1)
EMPTY FLAG/OUTPUT READY (EF/OR) #1
EMPTY FLAG/OUTPUT READY (EF/OR) #2
GATE
(1)
(4)
PROGRAMMABLE ALMOST EMPTY (PAE) #1
PROGRAMMABLE ALMOST EMPTY (PAE) #2
AND
GATE
(4)
PROGRAMMABLE ALMOST EMPTY (PAE) #1
PROGRAMMABLE ALMOST EMPTY (PAE) #2
AND
GATE
m + n
m
Qm+1 - Qn
n
DATA OUT
Q0 - Qm
6723 drw39
NOTES:
1. An OR gate is used for FWFT mode, AND gate for IDT mode.
2. Do not connect any output control signals directly together.
3. FIFO #1 and FIFO #2 must be the same depth, but may be different word widths.
4. PAE/PAF[1:2] optional, see section of external gating of output flags.
5. Recommend IDT74LVC32A 2-Input Positive OR Gate. Recommend IDT74LVC08A 2-Input AND Gate.
Figure 32. Block Diagram of 524,288 x 72 Width Expansion
DEPTH EXPANSION CONFIGURATION (FWFT MODE ONLY)
outputOR[1:2]andIR[1:2]pins.Twosets ofORgates areusedinthis mode
TheIDT72T36135Mcaneasilybeadaptedtoapplicationsrequiringdepths toderiveafeedbacklooptotheRENandWENpinstoavoidwritingorreading
greaterthanand524,288withan36-bitbuswidth.InFWFTmode,theFIFOs to/from a device when the device is not ready to accept data. The 2nd row of
canbeconnectedinseries(thedataoutputsofoneFIFOconnectedtothedata ORgatestakeintheIRorORpin’sstatusandallowfordatatobewritten/read
inputsofthenext)withnoexternallogicnecessary. Theresultingconfiguration tothe nextFIFOinthe chain. Ifthe IR orOR pins are low, this willenable the
providesatotaldepthequivalenttothesumofthedepthsassociatedwitheach devicetoacceptwritesorreadsfromthenextdeviceinline.Tousethismode,
singleFIFO. Figure33shows adepthexpansionusingtwoIDT72T36135M theFIFOdevice’sclockspeeddependsontheaddedpropdelayofthe“OR”
devices.
gatesandsetuptimebetweenthetwoFIFOdevices.Example,ifthe“OR”gates
Fordepthexpansionmode option#1, “logicalORgates”needtobe used beingusedhaveacombined10nspropagationdelay,a1nsjitterbudget,and
todrivetheactivelowinputWENandRENpinsrespectivelyfromtheactivelow 1nsclockskewmargin,12nsmustbetakenintoaccountduringeachclockcycle.
FEBRUARY04,2009
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IDT72T36135M 2.5V 18M-BIT TeraSync
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™ 36-BIT FIFO
COMMERCIAL AND INDUSTRIAL
TEMPERATURE RANGES
Forinstance,a25MHzclockhasarounda40nsclockcycle. Fora45%-55%
clockdutycycle,18nsaccountfor45%ofthedutycyclewhentheclockishigh.
Thismeans,18ns–12ns=6nsofsetuptimefordatatobeavailableatthe2nd
IDTFIFOwhichisfineconsideringthesetuptimeforthisFIFOisaround1.5ns.
Designersmustleaveanadequatetimingwindowtoallowdatatobecaptured
bythe2nd IDTFIFO. Pleasetakethisintoconsiderationwhenusingthisdepth
expansionmodetoavoiddatameta-stabilityissues. Forbufferinggreaterthan
18Mbitsathigherfrequencies,IDTrecommendsusingtheIDTSequentialFlow
Controller(SFC). PleaseseeIDTFlow-ControlManagement(FCM)product
websiteformoreinformationontheSFC.
CareshouldbetakentoselectFWFTmodeduringMasterResetforallFIFOs
in the depth expansion configuration. The first word written to an empty
configurationwillpassfromoneFIFOtothenext("rippledown")untilitfinally
appears at the outputs of the last FIFO in the chain – no read operation is
necessarybuttheRCLKofeachFIFOmustbefree-running. Eachtimethedata
wordappearsattheoutputsofoneFIFO,thatdevice'sOR[1:2]linegoesLOW,
enabling a write to the next FIFO in line. OR gates are used to take in the
considerationsofthenextFIFOinthechainsIRpinstatus.IftheIRpinsareLow,
thiswillenablethedevicetoacceptwritesfromupstreamdevices.
The"rippledown"delayisonlynoticeableforthefirstwordwrittentoanempty
depthexpansionconfiguration. Therewillbenodelayevidentforsubsequent
wordswrittentotheconfiguration.
The first free location created by reading from a full depth expansion
configurationwill"bubbleup"fromthelastFIFOtothepreviousoneuntilitfinally
movesintothefirstFIFOofthechain. Eachtimeafreelocationiscreatedinone
FIFOofthechain,thatFIFO'sIR[1:2]linegoesLOW,enablingthepreceding
FIFO to write a word to fill it.
Forafullexpansionconfiguration,theamountoftimeittakesforIR[1:2]ofthe
firstFIFOinthechaintogoLOWafterawordhasbeenreadfromthelastFIFO
is thesumofthedelays foreachindividualFIFOandthesumoftheORgate
prop delays:
(N – 1)*(3*transfer clock) + 2 TWCLK + 2 *OR prop delay
where N is the number of FIFOs in the expansion and TWCLK is the WCLK
period. NotethatextracyclesshouldbeaddedforthepossibilitythatthetSKEW1
specificationisnotmetbetweenRCLKandtransferclock,orWCLKandtransfer
clock,fortheIR[1:2]flag.
TheTransferClocklineshouldbetiedtoeitherWCLKorRCLK,whichever
isfaster. Boththeseactionsresultindatamoving,asquicklyaspossible,tothe
endofthechainandfreelocations tothebeginningofthechain.
Depth Expansion Option #2 is depicted in Figure 34, Depth Expansion
Option#2. OnedevicewillbeactiveatatimebytogglingtheWCSpins. Data
willbewrittenintoFIFOinPingPongfashion.FirstdataiswrittenintoFIFO#1,
seconddataiswrittenintoFIFO#2,thirddataiswrittenintoFIFO#1,fourthdata
iswrittenintoFIFO#2,andsoon. Datacanthenbereadoutinthesamemanner
on the read side by toggling the RCS1 and RCS2.
Foranemptyexpansionconfiguration,theamountoftimeittakesforOR[1:2]
ofthelastFIFOinthechaintogoLOW(i.e.validdatatoappearonthelastFIFO's
outputs)afterawordhasbeenwrittentothefirstFIFOisthesumofthedelays
for each individual FIFO and the sum of the OR gate prop delays:
(N – 1)*(4*transfer clock) + 3*TRCLK + 2 *OR prop delay
whereNisthenumberofFIFOsintheexpansionandTRCLKistheRCLKperiod.
Note that extra cycles should be added for the possibility that the tSKEW1
specificationisnotmetbetweenWCLKandtransferclock,orRCLKandtransfer
clock,fortheOR[1:2]flag.
FWFT/SI
TRANSFER CLOCK
FWFT/SI
FWFT/SI
WRITE CLOCK
READ CLOCK
WCLK
WEN
IR
RCLK
WCLK
RCLK
RCS
REN
READ CHIP SELECT
READ ENABLE
OR1
OR2
OR
GATE
OR
GATE
WRITE ENABLE
INPUT READY
WEN
IR1
IDT
72T36135M
OR
GATE
IDT
72T36135M
OR
GATE
REN
RCS
OE
IR2
OUTPUT READY
OR
OE
OUTPUT ENABLE
GND
n
DATA OUT
n
n
Qn
DATA IN
Dn
Dn
Qn
6723 drw40
Figure 33. Depth Expansion Option #1
FF1
EF1
WCS1
IDT
RCS1
36
72T36135M #1
36
REN
RCS2
IDT
72T36135M #2
WEN
EF2
WCS2
FF2
6723 drw41
Figure 34. Depth Expansion Option #2
FEBRUARY04,2009
47
ORDERINGINFORMATION
XXXXX
X
XX
X
X
X
Process /
Temperature
Range
Device Type Power Speed Package
BLANK
I(1)
Commercial (0° C to +70° C)
Industrial (-40° C to +85° C)
Green
G
Plastic Ball Grid Array (PBGA, BB240-1)
BB
5
6
Commercial Only
Commercial and Industrial
Clock Cycle Time (tCLK
Speed in Nanoseconds
)
L
Low Power
72T36135M 524,288 x 36 ⎯ 2.5V 18M-Bit High-Speed TeraSync™ FIFO
6723 drw42
NOTES:
1. Industrial temperature range product for 6ns speed grade is available as a standard device. All other speed grades are available by special order.
2. Green parts are available. For specific speeds and packages please contact your sales office.
DATASHEETDOCUMENTHISTORY
09/01/2005
02/28/2006
05/29/2006
02/04/2009
pg. 1.
pg. 10.
pgs.10, 21, and 23.
pg. 48.
CORPORATE HEADQUARTERS
6024 Silver Creek Valley Road
San Jose, CA 95138
for SALES:
for Tech Support:
408-360-1753
email:FIFOhelp@idt.com
800-345-7015 or 408-284-8200
fax: 408-284-2775
www.idt.com
48
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